Ultra-Wideband Transceiver MMIC Tuneable From 74.1 GHz to 147.8 GHz in SiGe Technology

As the use of integrated radar sensors is becoming more common not only in traditional military and automotive but also in medical and industrial applications, the requirements for a radar sensor diversify. For some applications, bandwidth is critical, primarily defining the capability to distinguish targets. Mostly, varying the frequency of an oscillator in the mmWave and THz range is realized by tuning a dc voltage to a variable capacitance. While this is typical for integrated transceivers in silicon-germanium (SiGe) technology, the tunability of a single voltage-controlled oscillator (VCO) limits the bandwidth. This work presents an approach to overcome this limitation by using two simultaneously tuned VCOs combined with a mixer. The oscillators are tuned simultaneously in opposing directions, resulting in an ultra-wideband signal at the mixer's output. The resulting tuning range is the addition of both of the VCOs' respective tuning ranges. The transceiver is realized using the B11HFC SiGe technology, featuring VCOs at center frequencies of 52 GHz and 108 GHz, respectively. The transceivers' output with a center frequency of 111 GHz is continuously tunable over a range of 73.6 GHz (66%). Furthermore, the phase noise contributions from both VCOs along a receiver test are presented.