Com-Power AH-840 User Manual

Features

Broadband - 18 GHz to 40 GHz

High gain

Individual calibration

Two year warranty

Horn Antenna

AH-840

Description

Model AH-840 is a broadband linearly polarized
double ridged waveguide horn antenna designed
specifically for Electromagnetic Interference
testing. This antenna can be used for receiving
as well as transmitting applications for the fre­quency range of 18 GHz to 40 GHz.

This antenna has a high gain; least 20 dBi over
the entire frequency range. This antenna can
accept up to 5 Watts of input power at its termi­nals in continuous mode for generating electro­magnetic fields for immunity testing.

The AH-840 Horn antenna has a K type connec­tor which can mate with SMA type connectors.
The antenna is constructed using lightweight
aluminum with corrosion resistant finish. The
oval rear plate has a 1/4" x 20 threaded hole for
mounting it to Com-Power AT-100 tripod.

The antenna is individually calibrated at 1 meter
and data and certificate of calibration will be
shipped with the antenna. The data will include
the antenna factor and gain of the antenna.

Com-Power Corporation (949) 587 - 9800 www. com-power.com [e-mail]

Application

The AH-840 was designed for EMC testing, but
it can also be used for antenna gain pattern
measurements, surveillance, and other applica­tions. The wide frequency band makes the AH­840 antenna suitable for sweep measurements,
reducing the need for antenna switching during
the tests.

High gain reduces the input power requirement
to achieve the desired field levels for immunity
testing and improves antenna sensitivity to low
level signals. During emissions testing the mea­sured field strength can be calculated by adding
the antenna factor for the particular frequency to
voltage measured at the antenna output terminal.

For immunity measurements, the input power
requirement P in Watts to generate E Electric
Field Strength in V/m at a distance D in meters
can be calculated by using the following for­mula:

P = E2 x D2 / 30 x N
N = 10
G = 20 log F -29.79- AF

Where

N = Numeric Gain
G = gain in dBi
F = Frequency in MHz
AF = antenna factor in dB/m

(G/10)

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Specifications

Frequency Range: 18 GHz - 40 GHz
Power handling: 5 Watts CW
VSWR: 2.0 :1.0
Connector type: K type female
Polarization: Linear
Impedance: 50 Ohms
Weight: 2 lbs. max. (0.9 kg)
Size (L xW xH): 8.7 x 2.7 x 7.5" inches

22 x 6.8 x 19.0 cm

Typical Antenna Factors:

50

45

40

35

30

Factors (dB/m)

25

Mounting Plate

SideView

2.0"

8.7"

Top View

7.5"

2.7"

5.7"

20

18 20 22 24 26 28 30 32 34 36 38 40

Frequency (GHz)

Field strength (dBV/m) = Output measured (dBV) + Antenna Factor (dB/m)

Typical Antenna Gain & Power requirement inWatts at a one meter distance
to obtain field strength in V/m:

Freq. Gain Freq. Field Strength

GHz (dBi) GHz V/m V/m V/m

10 20 100

18 21.12 18 0.03 0.10 2.58
19 20.79 19 0.03 0.11 2.78
20 21.63 20 0.02 0.09 2.29
22 24.06 22 0.01 0.05 1.31
24 25.01 24 0.01 0.04 1.05
26 25.01 26 0.01 0.04 1.05
28 23.45 28 0.02 0.06 1.51
30 23.65 30 0.01 0.06 1.44
32 23.91 32 0.01 0.05 1.35
34 23.94 34 0.01 0.05 1.35
36 23.34 36 0.02 0.06 1.55
38 21.61 38 0.02 0.09 2.30
40 21.05 40 0.03 0.10 2.62

All values are typical values unless specified.
Dimensions are given in inches unless specified
Last update: 1/02

Com-Power Corporation 20621 Pascal Way, Lake Forest, California 92630 (949) 587 - 9800 www.com-power.com Rev: 0102

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