A novel low-cost beam-steering technique based on the extended-resonance power-dividing method
A novel phased array based on the extended-resonance power-dividing method has been presented. This method eliminates the need for separate power splitter and phase shifters in a conventional phased-array system, resulting in a substantial reduction in circuit complexity and cost. As a proof of principle, a 2-GHz extended-resonance-based phased array using varactor diodes and microstrip patch antennas has been designed, fabricated, and tested. The measured scan range is 20/spl deg/ and the measured efficiency of the extended-resonance phased-array feed is typically 80%, which corresponds to 1 dB of insertion loss.
A Ka band extended resonance power amplifier
A Ka-band power amplifier based on an extended resonance power combining technique is presented. This technique enables the design of planar microstrip power amplifiers that are much more compact than those based on traditional quarter-wave hybrid designs. The extended resonance power combining amplifier presented here combines four GaAs MESFETs at 32.8 GHz using a planar structure that is more than 40% smaller than a quarter-wave hybrid power combining amplifier design, while the power-combining efficiency is 92%. The measured small-signal gain at 32.8 GHz is 4.6 dB, and at 1-dB compression the output power is 23.3 dBm with a power-added efficiency of 12.8%.
Ceramic phase-shifters for electronically steerable antenna systems
There is considerable interest in the development of microwave ceramic phase shifters because of limitations of currently available ferrite and PIN diode phase shifters regarding cost and reliability and complexity. Ceramic phase shifters may provide a cost breakthrough for the phase array antenna designer while maintaining low insertion loss and low drive power and high power handling capacity. This paper describes a ceramic phase shifter which utilizes a ferroelectric material for obtaining phase shifts from changes in dc biasing fields. Also, the dielectric properties were measured as a function of dc biasing fields, frequency, and temperature for a few compositions of barium-strontium titanate material.