An Active Bi-Directional SiGe DPDT Switch With Multi-Octave Bandwidth

This letter proposes a wideband active double-pole double-throw (DPDT) switch for wideband phased array antennas, which realizes multi-octave bandwidth with positive gain and 4-way switching operation using a bi-directional distributed amplifier technique. The measured gain is 2.0-6.0 dB and the input and output return losses are better than 9 dB from 2-22 GHz. The isolation is over 15 dB and the measured input P1dB is greater than -9.1 dBm and the output P1dB is greater than -7.8 dBm from 2-22 GHz. The chip size is 1.07 × 0.98 mm
²
including pads. The switch consumes 10 mA from a 2.5 V supply. Almost identical RF performance is achieved in each of the 4-way switching operations due to a symmetric circuit topology and careful layout. To the authors' knowledge, this is the first demonstration of the active DPDT switch configuration.