BACKGROUND

Wireless systems operate over a range of frequencies. Each frequency range has its own requirements for operation with desired performance. For example, millimeter wavelength applications have emerged to address the need for higher bandwidth and data rates. The millimeter wavelength spectrum covers frequencies between 30 GHz and 300 GHz and is able to reach data rates of 10 Gbits/s or more with wavelengths in the 1 to 10 mm range. The shorter wavelengths have distinct advantages, including better resolution, high frequency reuse and directed beamforming that are critical in wireless communications and autonomous driving applications. The shorter wavelengths are, however, susceptible to high atmospheric attenuation and have a limited range (just over a kilometer).

In many of these applications, phase shifters are needed to achieve a full range of phase shifts to direct beams to desired directions. Designing millimeter wave phase shifters is challenging as losses must be minimized in miniaturized circuits while providing phase shifts anywhere from 0 to 360°. The circuits and systems designed for one frequency may perform poorly at other frequencies, such as with the introduction of losses, parasitic effects, and so forth.

