The model AHA-118 double ridged waveguide horn antenna is basically the AH-118 antenna with an integrated preamplifier. The preamplifier has a nominal gain of 40 dB for the entire frequency range. The preamplifier improves the effective system noise performance for emissions testing as explained below. The antenna AH-118 is linearly polarized and has a frequency range of 700 MHz -18 GHz.
The output of the antenna is connected to the preamplifier by a short low loss cable, which can be removed. This arrangement makes it possible to (1) insert a filter before the amplifier and (2) use the antenna alone for transmission. The filter insertion capability is important and is required in presence of a high-level signal (such as fundamental frequency), which possibly could saturate the amplifier if the filter is not used. The transmitted signal flow is in opposite direction and uses a higher power level. Both conditions could damage the preamplifier if not removed.
This antenna is constructed using lightweight aluminum with a corrosion resistant conductive coating. The rear mounting plate of the AHA-118 has 1/4 inch x 20 threads. These threads allow the antenna to be mounted on a model AT-812 antenna tripod or any tripod with similar mounting arrangement. The antenna is powered by an supplied external DC wall mount adapter.
Most EMI test standards require the use of horn antennas for testing above 1 GHz. However, low amplitude signals are difficult to measure without amplification. The built-in preamplifier amplifies the received signals immediately at the antenna output increasing signal strength. This allows the low signals to be seen above the noise floor of the EMC receiver.
This waveguide antenna is an excellent choice for EMC radiated emissions testing above 700 MHz.Features:
|Product Name:||Double Ridged Waveguide Horn Antenna (built-in Preamplifier)|
|Frequency Range:||1 GHz to 18 GHz (usable from 700 MHz)|
|Nominal Impedance:||50 Ω|
|Power Handling:||300 Watts (continuous)|
|Preamplifier Gain:||40 dB (±2.5 dB)|
|P out @ 1 dB Compression:||+12 dBm|
|RF Connectors:||Precision N-type (female)|
|Active Antenna Factor:||-13.1 to 11.3 (average: -0.4) [dB(m-1)]|
|Active Isotropic Gain:||43.2 to 53.6 (average: 48.6) dBi|
|VSWR (antenna input):||1.58 to 3.32 (average: 2.23) :1|
|Return Loss (antenna input):||5.4 to 12.9 (average: 8.8) dB|
|Specifications:||FCC, CISPR, EN, ETSI, FAA, MIL-STD-461, SAE, etc.|
|Dimensions (H x W x D):||14.2 x 24.1 x 25.9 cm [5.6” x 9.5” x 10.2”]|
|Weight:||1.8 kg [ 4 lbs.]|