Ka-band Electrically Switchable Slotted Waveguide Antenna

The antenna system consists of four independent slotted waveguide sections shown in Fig. 1 together with a radar T/R-module. Each antenna section forms the radiation pattern with the beamwidth of 10° in the elevation plane and 2° in the azimuth plane. The antenna beams are displaced with the step of 16° in the elevation plane providing the total observation sector of about 60° as indicated in Fig. 2

Ka-band Slotted Waveguide Antenna Fig. 1. Ka-band Slotted Waveguide Antenna

Ka-band Slotted Waveguide Antenna Fig. 2. Ka-band Slotted Waveguide Antenna Operation Mode

Each antenna section is protected from moisture and dust with a simple cap (not shown in Fig. 1) made of laminated foam polystyrene.The sections are switched electrically by using an original high power reciprocal SP4T switch based on P-i-N diodes. The switch is based on three waveguide Y-junctions connected as a binary tree. The maximum peak power for such configuration is as high as 2.5 kW with the switching time as low as 1 μsec. The bandwidth of the switch is about ±3 %.

Antenna Characteristics

Operating bandwidth, GHz 0.4 (in Ka-band)
Beam type fan
3dB beam width in E-plane, deg 10
Observation sector in E-planes, deg 60
3dB beam width in H-plane, deg 2
Polarization Linear/Vertical
Side lobes level, dB <-22
Gain, dB >31
VSWR <1.2
Antenna section switching time, μsec 1
Dimensions of each antenna section, mm 310 x 70 x 8
Weight, kg 0.3