Low-loss, broad band, LC I/Q phase shifter

摘要

Some embodiments relate to a phase shifter that includes an I/Q phase shifter and at least one LC balun. Compared to conventional phase shifters, phase shifter has primarily only LC components, thereby limiting losses relative to conventional solutions. In one embodiment, for example, a phase shifter shows a large bandwidth at 77 GHz center frequency (e.g., 1 dB amplitude error bandwidth is approximately 40 GHz; 1° phase error bandwidth is about 16.5 GHz). The inductors included in phase shifter, in contrast to the quarter wave transmission lines used in conventional phase shifters, reduces chip area compared with conventional solutions. In some embodiments, an emitter follower helps to provide a relatively constant output that is largely independent of temperature, input power, VCC, manufacturing variation, and so on.

主权项

1. A phase shifter, comprising:
an I/Q phase shifter including an I-LO path having a single-ended I-LO output and a Q-LO path having a single-ended Q-LO output; a first LC balun having a single-ended input coupled to the single-ended I-LO output and having differential output terminals; a first emitter follower having first and second control terminals coupled to the respective differential output terminals of the first LC balun; a second LC balun having a single-ended input coupled to the single-ended Q-LO output and having differential output terminals; and a second emitter follower having first and second control terminals coupled to the respective differential output terminals of the second LC balun.