A D-band 180° phase shifter with very low amplitude- and phase-error

Phase shifters are at the heart of phased array systems which enable beam steering techniques. This paper presents a 180° digital phase shifter MMIC employing two SPDT switches which are realized in a 50nm metamorphic high electron mobility transistor technology. For the phase difference generation two identical couplers with different terminations are used. The measurement results show only 0.1dB amplitude imbalance and less than +/- 3:5° phase imbalance between 115 and 155GHz. The transmission loss is less than 5.6dB and the input and output matching are better than -10dB in the considered frequency range. The fabricated chip-size is 1.25 * 0.75mm(2) including the test pads.