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Acompacthigh-powerfeedforpowerdistributioninthehorizontalplaneofaC-bandplanar-array antenna is described. A combination of WR159 branch-guide couplers and of airdielectric-striptine powerdividersprovideshighpower-handlingcapacityinthelimitedspaceavailable. Theseries-parallel feed architecture and phase-compensating waveguide sections have a calculated instantaneous signal order to minimize the effect of varying impedances which typically occur in a scanning array bandwidth greater than 200 MHz. Four-port couplers and power dividers are used throughout in antenna.

The design and test results of an improved C-band four-bit PIN-diode phase shifter are described. Exceptional wideband performance is achieved through the use of a novel planar, s t r i e l i n _~y b~~. c u p ! e r t h a t is used in the 90-degree and 180-degee phase b~t s . The measured amplitude and phase flatness versus frequency of these phase bits exceeds the theoretical bandwidth characteristics of a conventional hybrid ring by itself. For BITE implementation, the PIN diodes are mounted to allow bias voltage and current of each diode to be monitored individually.

The design and fabrication of an affordable, all-machined, precision serpentine feed for application to a large S-band planar array antenna is described. By using reduced-height guides, it is possible to include both main and coupled waveguide channels within the periodic array spacing of approximately two inches.