ACTIVE ANTENNAS

Active antennas are fully-integrated radiating systems. They include an antenna and associated RF electronics. The RF electronics chain may include beamformers, filters, LNAs, mixers, down-converters, switches, and bias and BIT circuitry. The RF chain may be fully integrated into a single circuit board or it may consist of separate components.

Seavey Engineering provides custom active antennas to solve demanding cost, packaging and design requirements. The following examples are typical of such projects. Call us with your requirements.

Model 9835-800 DARS Subscriber
Antenna System

This system is used as an external antenna for reception of Digital Audio Radio (DARS) signals from geostationary satellites. It consists of a 12.5 dBic gain flat panel patch array and a special filter/amplifier/switch package. The system operates from 1.452 - 1.492 GHz. The antenna is dual circular polarized with one LNA for each polarization. Each 35 dB gain LNA is switched on-off through a high/low bias signal. The entire system incorporates 3-volt RF components. Current drain is only 20 ma.

pg65a

Model 9835-800
Low-cost DARS Subscriber System

Model 9758-810 - Dual-band (2.4 / 5.8 GHz)
RFID Reader System

Packaged in a small plastic enclosure, this low-cost system is installed within buildings and interrogates RFID tags. The system locates the tags within the building. The reader system incorporates two air-substrate circularly-polarized patch arrays. These arrays interface with circuit boards containing the RF and spread-spectrum signal processing circuits. A single port is output. The entire reader is supplied with the antenna, circuit board, plastic enclosure and wall mount. Extensive production test procedures ensure high product reliability.


pg65c
Model 9758-810
Dual-band RFID Reader System

 
Model 9317-800 - Dual-band (2.4 / 5.8 GHz)
Flat Panel WLAN System

This attractively-packaged indoor antenna system is used in campus-type WLAN installations. The antenna can radiate through building window glass. It is a three-layer, dual-band two-port patch array measuring about 16-inches square. The RF chain consists of a filter/LNA subassembly at one port and a filter/HPA at the other port. Bias signals are separately ported. A universal mount is provided.

pg65b

Model 9317-800
Dual-band WLAN System

Model 8851-899 - Vehicular Satellite Antenna

Designed for the Geostar location and messaging system, this low-cost omnidirectional antenna mounts onto trucks and other vehicles. It combines three functions in one rugged package. It includes a Loran-C whip antenna with its associated buffer amplifier. An L-band circularly-polarized omni patch antenna is used for the satellite uplink. C-band downlink signals use a vertically-polarized conical omni antenna. A C-band low-noise downconverter (LNC) is included with this active antenna system.

 Model 9652-800 - Airborne GPS Omni Antenna

This is a quadrifilar helix antenna operating at the GPS L1 frequency. It includes a TOKO 4DFA bandpass filter and a low-cost LNA with a noise figure of 1.2 dB. Elevation coverage is 20° - 70° at a gain of 3.5 dBic. The antenna is suitable for use on light aircraft

pg65d

Model 9652-800
Airborne GPS Omni