Comtech EF Data SFC4200 User Manual

SFC4200/SFC1275G

Synthesized Frequency

Downconverter

Installation and Operation Manual

TM054 - Rev. 4.0

March, 2002

- NOTICE -

2002, Radyne ComStream Corporation. This
manual may not in whole or in part be copied,
reproduced, translated or reduced to any
electronic or magnetic storage medium without
the written consent of a duly authorized officer
of Radyne ComStream Corporation.

Radyne ComStream Corporation •• 3138 E. Elwood St. •• Phoenix, AZ 85034 •• [phone] •• Fax: [phone]

Latest Software Revision Confirmation

When new features are added to Radyne ComStream Corporation
equipment, the control parameters are appended to the end of the
Non-Volatile Section of the Remote Communications Specification,
and status of the features, if any, are added at the end of the Volatile
Section. If a remote M&C queries two pieces of Radyne ComStream
Corporation equipment with different revision software, they could
respond with two different sized packets. The remote M&C MUST
make use of the non-volatile count value to index to the start of the
Volatile Section. If the remote M&C is not aware of the newly added
features to the product, it should disregard the parameters at the end
of the Non-Volatile Section and index to the start of the Volatile
Section.

Before creating any software based on the information contained in
this document, contact the Radyne ComStream Corporation Customer
Service Department (602-437-9620) to find out if the software revision
for that piece of equipment is current and that no new features have
been added since the release of this document.

Warranty Policy DM240 Synthesized Frequency Downconverter

2

SFC4200/SFC1275G Synthesized Frequency Downconverter Warranty Policy

Radyne ComStream Corporation Warranty Policy

Warranty and Service

Radyne ComStream Corporation (Seller) warrants the items manufactured and sold by Radyne
ComStream Corporation to be free of defects in material and workmanship for a period of two (2) years
from date of shipment Radyne ComStream Corporation's obligation under its warranty is limited in
accordance with the periods of time and all other conditions stated in all provisions of this warranty.

This warranty applies only to defects in material and workmanship in products manufactured by Radyne
ComStream Corporation. Radyne ComStream Corporation makes no warranty whatsoever concerning
products or accessories not of its manufacture. Repair, or at Radyne ComStream Corporation's option,
replacement of the Radyne ComStream Corporation products or defective parts therein shall be the sole
and exclusive remedy for all valid warranty claims.

Warranty Period

The applicable warranty period shall commence on the date of shipment from Radyne ComStream
Corporation's facility to the original purchaser and extend for the stated period following the date of
shipment. Upon beginning of the applicable Radyne ComStream Corporation warranty period, all
customer's remedies shall be governed by the terms stated or referenced in this warranty. In-warranty
repaired or replacement products or parts are warranted only for the remaining unexpired portion of the
original warranty period applicable to the repaired or replaced products or parts. Repair or replacement of
products or parts under warranty does not extend the original warranty period.

Warranty Coverage Limitations

The following are expressly not covered under warranty:

1. Any loss, damage and/or malfunction relating in any way to shipping, storage, accident, abuse,
alteration, misuse, neglect, failure to use products under normal operating conditions, failure to
use products according to any operating instructions provided by Radyne ComStream
Corporation, lack of routine care and maintenance as indicated in any operating maintenance
instructions, or failure to use or take any proper precautions under the circumstances.

2. Products, items, parts, accessories, subassemblies, or components which are expendable in

normal use or are of limited life, such as but not limited to, bulbs, fuses, lamps, glassware, etc.
Radyne ComStream Corporation reserves the right to revise the foregoing list of what is covered
under this warranty.

Warranty Replacement and Adjustment

Radyne ComStream Corporation will not make warranty adjustments for failures of products or parts which
occur after the specified maximum adjustment period. Unless otherwise agreed, failure shall be deemed to
have occurred no more than seven (7) working days before the first date on which a notice of failure is
received by Radyne ComStream Corporation. Under no circumstances shall any warranty exceed the
period stated above unless expressly agreed to in writing by Radyne ComStream Corporation.

Liability Limitations

This warranty is expressly in lieu of and excludes all other express and implied warranties, Including but
not limited to warranties of merchantability and of fitness for particular purpose, use, or applications, and
all other obligations or liabilities on the part of Radyne ComStream Corporation, unless such other
warranties, obligations, or liabilities are expressly agreed to in writing by Radyne ComStream Corporation.

All obligations of Radyne ComStream Corporation under this warranty shall cease in the event its products
or parts thereof have been subjected to accident, abuse, alteration, misuse or neglect, or which have not
been operated and maintained in accordance with proper operating instructions.

TM054 – Rev. 4.0 iii

Warranty Policy SFC4200/SFC1275G Synthesized Frequency Downconverter

In no event shall Radyne ComStream Corporation be liable for Incidental, consequential, special or
resulting loss or damage of any kind howsoever caused. Radyne ComStream Corporation’s liability for
damages shall not exceed the payment, if any, received by Radyne ComStream Corporation for the unit or
product or service furnished or to be furnished, as the case may be, which is the subject of claim or
dispute.

Statements made by any person, including representatives of Radyne ComStream Corporation, which are
inconsistent or in conflict with the terms of this warranty, shall not be binding upon Radyne ComStream
Corporation unless reduced to writing and approved by an officer of Radyne ComStream Corporation.

Warranty Repair Return Procedure

Before a warranty repair can be accomplished, a Repair Authorization must be received. It is at this time
that Radyne ComStream Corporation will authorize the product or part to be returned to the Radyne
ComStream Corporation facility or if field repair will be accomplished. The Repair Authorization may be
requested in writing or by calling:

Radyne ComStream Corporation

3138 E. Elwood St.
Phoenix, Arizona 85034 (USA)
ATTN: Customer Support
Phone: [phone] Fax: [phone]

Any product returned to Radyne ComStream Corporation for examination must be sent prepaid via the
means of transportation indicated as acceptable to Radyne ComStream Corporation. Return Authorization
Number must be clearly marked on the shipping label. Returned products or parts should be carefully
packaged in the original container, if possible, and unless otherwise indicated, shipped to the above
address.

Non-Warranty Repair

When a product is returned for any reason, Customer and its shipping agency shall be responsible for all
damage resulting from improper packing and handling, and for loss in transit, not withstanding any defect
or nonconformity in the product. By returning a product, the owner grants Radyne ComStream
Corporation permission to open and disassemble the product as required for evaluation. In all cases,
Radyne ComStream Corporation has sole responsibility for determining the cause and nature of failure,
and Radyne ComStream Corporation's determination with regard thereto shall be final.

iv TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Record of Revisions

SFC4200/SFC1275G Synthesized Frequency Downconverter

Installation and Operation Manual

TM054 – Record of Revisions

Radyne ComStream Corporation is constantly improving its products and therefore the
information in this document is subject to change without prior notice. Radyne ComStream
Corporation makes no warranty of any kind with regard to this material, Including but not limited
to the implied warranties of merchantability and fitness for a particular purpose. No responsibility
for any errors or omissions that may pertain to the material herein is assumed. Radyne
ComStream Corporation makes no commitment to update nor to keep current the information
contained in this document. Radyne ComStream Corporation assumes no responsibility for use
of any circuitry other than the circuitry employed in Radyne ComStream Corporation systems
and equipment.

Revision

Level

1.0 7-15-96 Initial Release

2.0 12-01-96 Added interconnection diagram, redefined connector pinouts, updated serial

2.1 12-16-96 Updated Operation Section, updated Serial Protocol and added additional

3.0 2-03-97 Updated Operation Section, added 1:1 and 1:8 Serial Protocol data.

3.1 4-24-97 Added Extended Band data, additional 1:8 operation data and backup 1:8

4.0 3-4-02 Merged with Rev. 4.0, TM062, SFC1275G Global Ku-Band Synthesized

Date Reason for Change

protocol, enhanced operation section, added remote serial I/O operation.
figures to Appendix C.

flow chart
Frequency Downconverter.

TM054 - Rev. 4.0 v

SFC4200/SFC1275G Synthesized Frequency Downconverter

This Page is Intentionally Left Blank

vi TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Table of Contents

Table of Contents

Section 1 - Introduction

1.0 Description______________________________________________________1-1

1.1 Protection Switch Versatility_________________________________________ 1-2

Section 2 - Installation

2.0 Installation Requirements __________________________________________ 2-1

2.1 Unpacking ______________________________________________________ 2-1

2.2 Removal and Assembly____________________________________________2-1

2.3 Mounting Considerations___________________________________________2-1

2.4 Initial Power-Up __________________________________________________2-1

2.5 SFC Downconverter Interconnections _________________________________ 2-2

Section 3 - Operation

3.0 Theory of Operation_______________________________________________3-1

3.1 Signal RF Assembly ______________________________________________3-1

3.1.1 AS/4010 Converter First Mixer C-Band Downconverter (SFC4200) _________ 3-2

3.1.2 AS/4011 Converter Second Mixer C-Band Downconverter (SFC4200) ______ 3-2

3.1.3 AS/4007 Converter First Mixer Ku-Band Downconverter (SFC1275G)_______3-3

3.1.4 AS/4012 Converter Second Mixer Ku-Band Downconverter (SFC1275G) ____3-3

3.2 AS/3048 M&C Controller Assembly___________________________________3-4

3.3 Synthesizer Modules ______________________________________________3-4

3.3.1 Synthesizer Module (SFC4200) ____________________________________3-5

3.3.2 Synthesizer Module (SFC1275G)___________________________________3-5

3.4 AS/3072 Frequency Reference Assembly______________________________ 3-7

3.5 AS/3228 Power Supply System______________________________________3-7

3.5.1 AS/3228 Output Board ___________________________________________3-7

3.6 Frequency Accuracy ______________________________________________ 3-8

3.7 Amplitude Accuracy_______________________________________________3-8

TM054 - Rev. 4.0 vii

Table of Contents SFC4200/SFC1275G Synthesized Frequency Downconverter

Section 4 – User Interfaces

4.0 User Interfaces __________________________________________________ 4-1

4.1 Front Panel User Interface__________________________________________4-1

4.1.1 Front Panel LED Indicators________________________________________4-1

4.1.2 Front Panel LCD Display _________________________________________ 4-2

4.1.3 Front Panel Keypad _____________________________________________4-4

4.1.3.1 Soft Reset ___________________________________________________4-4

4.1.4 Monitoring Ports ________________________________________________ 4-4

4.2 Menu Screens ___________________________________________________4-4

4.2.1 Root Menu ____________________________________________________4-8

4.2.1.1 Status ______________________________________________________ 4-9

4.2.1.2 Set/Change Status ___________________________________________4-10

4.2.1.3 Frequency __________________________________________________ 4-10

4.2.1.4 Gain_______________________________________________________ 4-11

4.2.2 Converter Type Menu___________________________________________4-11

4.2.3 Switch Fault Menu _____________________________________________4-11

4.2.4 Converter Faults Menu __________________________________________ 4-12

4.2.5 Utility Access Menus____________________________________________4-13

4.2.6 Switch Configuration Menu_______________________________________4-14

4.2.7 Learn Menu (Backup Converter Only) ______________________________ 4-14

4.2.8 Learn Status Menus (Backup Converter Only) ________________________4-14

4.2.9 Configuration Menu ____________________________________________ 4-15

4.2.10 Reference Menu______________________________________________4-16

4.2.10.1 Reference Offset____________________________________________4-17

4.2.10.2 Reference Stability __________________________________________4-17

4.2.11 Output Attenuator Calibration Menu _______________________________ 4-18

4.3 Serial Protocol __________________________________________________ 4-19

4.4 Command Structure______________________________________________4-19

4.5 Control Commands ______________________________________________4-20

4.5.1 Set Current Channel Frequency Command (S, P1:1, P1:8)______________4-20

4.5.2 Set Current Channel Gain Command (S, P1:1, P1:8) __________________4-20

4.5.3 Set Channel Command (S, P1:1, P1:8) _____________________________4-21

4.5.4 Store Current Channel Settings (S, P1:1, P1:8) _______________________4-21

4.5.5 Remote Help Menu (All) _________________________________________ 4-21

4.5.6 Status Command ______________________________________________4-21

viii TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Table of Contents

4.5.7 Clear Faults Command (All) ______________________________________4-22

4.5.8 Auto Mode Command (P1:1, B1:1, B1:8) ____________________________4-22

4.5.9 Manual Mode Command (P1:1, B1:1)_______________________________ 4-23

4.5.10 Manual Backup Command (B1:8)_________________________________4-23

4.5.11 Set Stored Gain For a Specified Channel (S, P1:1, P1:8) ______________4-23

4.5.12 Set Stored Frequency For a Specified Channel (S, P1:1, P1:8)__________4-23

4.5.13 Erase (All)___________________________________________________ 4-23

4.5.14 Restart (All)__________________________________________________4-24

4.5.15 Data (All)____________________________________________________4-24

4.5.16 Learn (B1:1, B1:8) ____________________________________________4-24

4.5.17 Show Priority (B1:8) ___________________________________________4-24

4.5.18 Set Priority (B1:8) _____________________________________________4-24

4.6 SFC Downconverter Operator Quick Reference Guide___________________4-25

Section 5 – Electrical Interfaces

5.0 SFC Downconverter Connections ____________________________________ 5-1

5.1 Power _________________________________________________________5-1

5.2 RF In (J1)_______________________________________________________5-1

5.3 IF Out (J2) ______________________________________________________5-1

5.4 10 MHz Ref Out (J3) ______________________________________________5-1

5.5 10 MHz Ref In (J4)________________________________________________5-1

5.6 B. U. Switch Interface (J5)__________________________________________5-1

5.7 Equipment RS-485 (J6)____________________________________________5-2

5.8 Test/Fault (J7) ___________________________________________________5-3

5.9 Operation Serial I/O (J8) ___________________________________________5-4

5.10 Coarse VCXO Adjustment_________________________________________5-7

5.11 Monitor Ports ___________________________________________________5-8

5.11.1 RF Monitor Port _______________________________________________5-8

5.11.2 IF Monitor Port ________________________________________________5-8

5.11.3 LO Monitor ___________________________________________________5-8

TM054 - Rev. 4.0 ix

Table of Contents SFC4200/SFC1275G Synthesized Frequency Downconverter

Section 6 - Maintenance

6.0 Periodic Maintenance _____________________________________________6-1

6.1 Failure Analysis __________________________________________________6-1

Section 7 - Technical Specifications

7.0 Introduction _____________________________________________________7-1

7.1 Input Characteristics ______________________________________________7-1

7.2 Output Characteristics_____________________________________________7-1

7.3 Transfer Characteristics____________________________________________7-1

7.4 Frequency Synthesizer ____________________________________________ 7-2

7.5 Single Side Band Phase Noise ______________________________________7-2

7.6 Rx Signal Strength Detection________________________________________7-2

7.7 Mechanical______________________________________________________ 7-2

7.8 Operator Interface ________________________________________________7-3

7.9 Environmental Characteristics_______________________________________7-3

Section 8 – Appendices

x TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Introduction

Section 1 - Introduction

1.0 Description

This manual discusses the Radyne ComStream Corporation SFC Synthesized Frequency
Downconverter family of products (Figure 1-1). These include the SFC4200 C-Band, and the
SFC1275G Ku-Band Synthesized Frequency Downconverters. They are high quality, rack
mounted satellite Downconverters that are intended for use in medium-to-large earth station
installations where multiple carrier uplinks need to be established. The SFC Downconverters are
ready to be configured into a variety of backup switch configurations which include 1:1, and 1:N
(to a maximum of N = 8) configurations.

The SFC4200 Downconverter is a C-Band, 125 kHz resolution synthesized satellite
downconverter capable of converting a C-band downlink in the range of 3.620 to 4.2 GHz or

3.400 to 4.2 GHz extended band, to either a 40 MHz bandwidth 70 MHz IF output or optionally to

an 80 MHz bandwidth 140 MHz carrier.
The SFC1275G Downconverter is a Ku-Band 125 KHz resolution synthesized satellite

downconverter capable of converting a Ku-Band downlink in the range of 10.95 to 12.75 GHz to
either a 40 MHz bandwidth 70 MHz IF output or optionally to an 80 MHz bandwidth 140 MHz
carrier.

Gain can be controlled to 0.1 dB step resolution. Control of frequency and gain can be
accomplished through the Front Panel Controls or remotely via an RS-232 Serial Interface.

The units monitor local oscillator (LO) phase-locked loop faults in the converter at all times
during operation. If a fault is detected, the converter immediately goes into the Off Line Mode.
If multiple converters are configured to provide backup protection switching, a summary fault will
signal the backup and put itself online thus restoring the failed circuit.

The RF Hardware consists of a broadband synthesizer, a fixed frequency phase locked oscillator,
and the first and second converter modules. The broadband synthesizer provides the
synthesized local oscillator for the conversion from RF to L-Band. The LO that tunes from

4.6645 – 5.2425 GHz or 4.485 – 5.335 GHz (SFC4200), or from 8.88 – 10.68 GHz (SFC1275G)

performs this conversion. The second mixer converts the L-Band Signal to either the 70 or 140
MHz IF Output. A fixed frequency IFLO performs this frequency conversion.

A 40 dB gain control output attenuator at the IF controls the power out of the converter. This
attenuator is capable of 0.1 dB resolution through a software linear interpolation of 1 dB
calibration values.

The internal IF is converted by the second mixer LO to 70 or 140 MHz. The 70/140 MHz IF
chain also performs filtering and phase equalization via an all-pass network. The gain calibration
process also provides gain slope across all bands to be within the specified ± 0.5 dB. Additional
gain compensation due to changes in ambient temperature provide for high gain stability over
various operating conditions.

Figure 1-1. SFC Downconverter Front Panel

TM054 - Rev. 4.0 1-1

Introduction SFC4200/SFC1275G Synthesized Frequency Downconverter

The SFC Downconverters have been designed to provide performance that meets or exceeds all
industry standards in effect today for satellite communications earth station frequency converter
equipment found worldwide. In addition to providing robust performance, the SFC
Downconverters are loaded with features that will provide ease of integration and operation.

1.1 Protection Switch Versatility

Radyne ComStream Corporation SFC family of Converter Products feature ‘plug-and-play’ ease
of installation with the RCU101 1:1 or the RCU108 1:8 Redundancy Control Units. All converters
can be plugged into the backup slot and assume the role of protection switch controller. The
backup converter learns and stores the frequency, gain and channel settings of the primary
converters. If the stored setting of the primary converter is changed, the backup converter will
notify the user via the front panel and the RS-232/RS-485 interface.

All circuits are protected upon installation of the switch and completion of the learning process.
This eliminates the need for complicated software configurations that might otherwise leave a
circuit vulnerable. Likewise, replacing a failed converter is as simple as plugging in a
replacement.

1-2 TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Installation

Section 2 - Installation

2.0 Installation Requirements

SFC Downconverters are designed to be installed within any standard 19 inch equipment cabinet
or rack, and requires 1 Rack Unit (RU) mounting space (1.75 inches) vertically and 19 inches of
depth. Including cabling, a minimum of 20 inches of rack depth is required. The rear panel is
designed to have power enter from the right and cabling enter from the center and left when
viewed from the rear of the unit. Data and control cabling can enter from either side. The unit
can be placed on a table or suitable stable surface if required.

Before initially applying power to the unit, it is a good idea to disconnect
the transmit output from the operating station equipment. This is
especially true if the current SFC Downconverter configuration settings are
unknown, where incorrect setting could disrupt existing communications
traffic.

2.1 Unpacking

The SFC Downconverter was carefully packaged to avoid damage and should arrive complete
with the following items for proper installation:

SFC Downconverter Unit
Power Cord, 6 foot with applicable AC Connector
Installation and Operation Manual

2.2 Removal and Assembly

Carefully unpack the unit and ensure that all of the above items are in the carton. If the Prime
AC power available at the installation site requires a different power cord/AC connector, then
arrangements to receive the proper device will be necessary before proceeding with the
installation.

SFC Downconverters are shipped fully assembled and do not require removal of the covers for
any purpose in installation. Should the AC Power Connector Cable be of the wrong type for the
installation, either the cable or the power connector end should be replaced. The power supply
itself is designed for universal application using from 100 to 240 VAC, 50 – 60 Hz.

2.3 Mounting Considerations

When mounted in an equipment rack, adequate ventilation must be provided. The ambient
temperature in the rack should be between 10°C and 35°C, and held constant for best equipment
operation. The air available to the rack should be clean and relatively dry.

2.4 Initial Power-Up

Turn the unit ‘ON’ by placing the rear panel switch (above the power entry connector) to the ‘ON’
position. Upon initial and subsequent power-ups, the SFC Downconverters will test themselves
and several of its components before beginning its main Monitor/Control program. These power­up diagnostics show no results if successful. If a failure is detected, the Fault LED is illuminated.

TM054 - Rev. 4.0 2-1

Installation SFC4200/SFC1275G Synthesized Frequency Downconverter

2.5 SFC Downconverter Interconnections

Figure 2-1 illustrates a typical interconnection of a SFC Downconverter with an RCU101 1:1
Protection Switch.

Figure 2-1. RCU101 Typical Interconnection with SFC Downconverters

2-2 TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Operation

Section 3 - Operation

3.0 Theory of Operation

The SFC Downconverters have been designed to minimize the amount of hardware in the
system while maximizing performance. Spurious performance in the Downconverter is critical
and in particular, LO related spurious In-Band is nonexistent.

The SFC Downconverters are double conversion microwave Downconverters. The block
diagram (Figure 3-1) of the system includes the Signal RF Assembly, the Synthesizer Assembly,
the Reference Assembly, the Monitor and Control (M&C) Microcontroller, and Power Supply
Subsystem.

Figure 3-1. SFC Downconverter Block Diagram

3.1 Signal RF Assembly

The Signal RF Assembly is a subassembly that holds the first and second mixer converter
modules, and the IF Cavity Filter. The first and second mixer modules for the SFC4200 and
SFC1275G Downconverters are described below.

TM054 - Rev. 4.0 3-1

Operation SFC4200/SFC1275G Synthesized Frequency Downconverter

3.1.1 AS/4010 Converter First Mixer C-Band Downconverter (SFC4200)

The First Mixer module of the C-Band Downconverter accepts the input and has 30 dB of digital
gain control. Performance specifications for the First Mixer are listed on Table 3-1.

Table 3-1. AS/4010 Converter First Mixer C-Band Downconverter (SFC4200)

Standard Band Extended Band

Input Frequency 3.62 – 4.2 GHz 3.400 – 4.200 GHz

Input Power -40 dB Nominal -40 dB Nominal

Input Return Loss > -20 dB > -20 dB

Input Impedance 50Ù 50Ù

Gain 8 – 10 dB 8 –10 dB

Gain Control None None

Output Frequency 1.0225 – 1.0626 GHz

(70 MHz)

0.9325 – 1.0125 GHz
(140 MHz)

P

Nominal -30 to –32 dBm -30 to –32 dBm

out

1.135 – 1.175 GHz
(70 MHz)

1.045 - 1.125 GHz
(140 MHz)

Output Impedance 50Ù 50Ù

LO Input 4.6625 – 5.2425 GHz @

+13 dBm for 70 MHz IF

4.5925 – 5.1725 GHz @

+13 dBm for 140 MHz IF

4.555 – 5.355 GHz @

+13 dBm for 70 MHz IF

4.485 – 5.285 GHz @

+13 dBm for 140 MHz IF

3.1.2 AS/4011 Converter Second Mixer C-Band Downconverter (SFC4200)

The Second Mixer module of the C-Band Downconverter accepts the IF from the First Mixer and
converts and amplifies it to the 70/140 MHz, 75Ù IF Output. The Second Mixer has 40 dB of
gain control. Performance of this converter assembly is listed in Table 3-2.

Table 3-2. AS/4011 Converter Second Mixer C-Band Downconverter (SFC4200)

Standard Band Extended Band

Output Frequency 50 – 90 MHz Standard

(100 – 180 MHz [Option 01])

50 – 90 MHz Standard

(100 – 180 MHz [Option 01])

Impedance 75Ù 75Ù

Output Return Loss

P

P1 dB +20 dBm +20 dBm

out

≥ 23 dB ≥ 23 dB

Gain 30 – 32 dB 30 – 32 dB

Input Frequency 1.0225 – 1.0625 GHz (70 MHz)

0.9325 – 1.0125 GHz (140 MHz)

Detected Output 0 - 10 VDC

(10 VDC @ -10 dBm Out)

3-2 TM054 - Rev. 4.0

1.135 – 1.175 GHz (70 MHz)

1.045 – 1.125 GHz (140 MHz)
0 - 10 VDC

(10 VDC @ -10 dBm Out)

SFC4200/SFC1275G Synthesized Frequency Downconverter Operation

0 – 10 VDC (10 VDC @ -10 dBm In with

LO 1.1125 GHz @ +13 dB 1.225 GHz @ +13 dB

3.1.3 AS/4007 Converter First Mixer Ku-Band Downconverter (SFC1275G)

The First Mixer module of the Ku-Band Downconverter accepts the 10.95 – 12.75 GHz Downlink
and converts it to L-Band IF. Performance specifications for the First Mixer are listed on
Table 3-3.

Table 3-3. AS/4007 Converter First Mixer Ku-Band Downconverter

(SFC1275G)

Input Frequency 10.95 – 12.75 GHz

Input Power -40 dBm

Input Return Loss > -18 dB

Input Impedance 50Ù

Gain -5 to 6 dB

Gain Control None

Output Frequency 2.050 – 2.070 GHz (70 MHz) 2.100 –

2.180 GHz (140 MHz)

P

Nominal -34 to -35 dBm

out

Output Impedance 50Ù

LO Input 8.88 – 10.68 GHz @ +13 dBm for 70

MHz IF

8.81 – 10.61 GHz @ +13 dBm for 140
MHz IF

3.1.4 AS/4012 Converter Second Mixer Ku-Band Downconverter
(SFC1275G)

The Second Mixer module of the Ku-Band Downconverter accepts the IF from the First Mixer
and converts and amplifies it to the 70 MHz, 75Ù IF Output. The Second Mixer has 40 dB of
gain control. Performance of this converter assembly is listed in Table 3-4.

Table 3-4. AS/4012 Converter Second Mixer Ku-Band

Downconverter (SFC1275G)

Output Frequency 50 – 90 MHz Standard (100 – 180

MHz [Option 01])

Impedance 75Ù

Output Return Loss < -23 dB

P

P1 dB +20 dBm

out

Gain 34 – 35 dB

Input Frequency 2.050 – 2.090 GHz (70 MHz)

Pin Nominal -34 to 35 dBm

Detected Output

TM054 - Rev. 4.0 3-3

Operation SFC4200/SFC1275G Synthesized Frequency Downconverter

0 dB Attenuation)

LO 2.0 GHz @ +13 dB

3.2 AS/3048 M&C Controller Assembly

The Controller PWB Assembly is the controller, which monitors the Operator Front Panel, and
Remote Input used to control the frequency, gain and provide the fault detection functions of the
converter. The AS/3048 hardware features an Intel 80C32 microprocessor (Refer to Figure 5-2).
Peripherals on the controller include the following:

12 Bit Digital to Analog Converter (DAC)
8 Channel/8 Bit Analog to Digital Converter (A/D)
RS-485 UART
RS-232, -422, -485 UART
LCD Port
8 Bit Addressable Synthesizer Bus
5 Bit Addressable Converter Bus
Static Memory
Nonvolatile Memory
Serial Nonvolatile Memory
Read-Only Memory (ROM)

The 12 Bit DAC provides the precise current to the PIN Diode Attenuators in the converter. The
value of attenuation is determined through look-up of calibration data stored in non-volatile
memory. 000 to FFF written to the DAC provides an output voltage of 0.3 V – 8.50 V
respectively.

The 8-channel A/D Converter allows the AS/3048 to monitor various voltages within the
converter. The input to the A/D is 0 to 5 VDC. Voltages monitored by the A/D include the
square-law voltages from the IF and Fault of the synthesizer which allows the controller to
calculate signal strengths.

The Equipment RS-485 UART is independent from the Operator UART. Dual UARTS allow
equipment to be tied together as a system while giving the operator a single remote point of
contact. The operator serial interface is configurable via jumpers found on the AS/3048. Refer
to Figure 5-3 for the location of the jumpers.

The various memories found in the AS/3048 provide for program storage and calibration value
storage. In the event that the operator is requested to perform a software revision, replacement
of the PROM (U11) will be required. This operation should be performed with the power off and
in a static-free environment.

3.3 Synthesizer Modules

The Synthesizer module used in SFC Downconverters are stand-alone modules that provide the
synthesized local oscillator and the fixed IF local oscillator for the first and second mixers in the
converter.

3-4 TM054 - Rev. 4.0

SFC4200/SFC1275G Synthesized Frequency Downconverter Operation

3.3.1 Synthesizer Module (SFC4200)

The 10 MHz reference to the synthesizer is provided by the AS/3072 Reference Assembly.
Performance of the synthesizer is listed in Table 3-5.

Table 3-5. Synthesizer Module (SFC4200)

Standard Extended

RF LO Output Frequency 4592.5 - 5242.5 MHz 4.48 – 5.355 GHz

Step Size 125 kHz 125 kHz

Power Out +13 dBm +13 dBm

Spurious -70 dBc -70 dBc

Harmonics -20 dBc -20 dBc

Phase Noise

Note: Typical readings are 3

to 8 dB better than shown.

IF LO Output Frequency 1112.5 MHz 1.225 GHz

Spurious -70 dBc -70 dBc

Harmonics -20 dBc -20 dBc

-70 dBc @ 100 Hz

-80 dBc @ 1 kHz

-88 dBc @ 10 kHz

-95 dBc @ 100 kHz

-110 dBc @ 1 MHz

-70 dBc @ 100 Hz

-80 dBc @ 1 kHz

-88 dBc @ 10 kHz

-95 dBc @ 100 kHz

-110 dBc @ 1 MHz

3.3.2 Synthesizer Module (SFC1275G)

The 10 MHz reference to the synthesizer is provided by the AS/3072 Reference Assembly.
Performance of the synthesizer is listed in Table 3-6.

Table 3-6. Synthesizer Module (SFC1275G)

RF LO Output Frequency 11.91 – 12.73 GHz

Step Size 125 kHz

Power Out 13 – 15 dBm

Spurious -70 dBc In-Band

-82 dBc Out-of Band

Harmonics -20 dBc

Phase Noise

Note: Typical readings are 3

to 5 dB better than shown.

IF LO Output Frequency 2.0 GHz

Spurious -70 dBc

Harmonics -20 dBc

TM054 - Rev. 4.0 3-5

-60 dBc @ 100 Hz

-80 dBc @ 1 kHz

-84 dBc @ 10 kHz

-94 dBc @ 100 kHz

-110 dBc @ 1 MHz