Broadband multi-octave receiver from 1–32 GHz for monolithic integrated vector network analyzers (VNA) in SiGe-technology

For monolithically integrated vector network analyzers (VNA) a broadband multi-octave receiver is shown, which exhibit a very wide frequency range from 1–32 GHz. It consists out of a low noise amplifier (LNA) and an active mixer, followed by an output buffer. With the presented design, a maximum achievable conversion gain (CG) of 16.6 dBm can be reached. The main design-goal is a very flat deviation of the conversion gain over five octaves, which eases calibration of the VNA. To realize variable gain functionality, without losing much input matching, special attention is spent to the design and topology of a new extended gain-control circuit (VGC) is shown. A second VGC is implemented in the output buffer, to improve isolation for deactivated channels of the VNA. All bandwidth extension techniques will be explained in detail and flesh out by simulations. Furthermore, a matching lower than −10 dB is achieved between 1 GHz and 28 GHz. The noise figure NFdsb of the broadband receiver is between 4.6 and 5.8 dB for 4–32 GHz and the output-referred 1-dB-compression-point of 0.1–4.3 dBm from 2–32 GHz. The current consumption at a supply voltage of 3.3 V has a value of 66 mA.