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This paper addresses the miniaturization of microwave vector network analyzers (VNAs) and the future vision of the VNA on a chip. Therefore, a highly integrated two-port VNA with a multioctave bandwidth from 4 to 32 GHz is presented. The proposed system is based on a fully integrated radio-frequency frontend consisting of a two-port stimulus, a four-channel heterodyne receiver, and a wideband testset. The testset is comprised of on-chip multisection directional couplers. The chip is operated inside a hardware demonstrator using a 16-term calibration procedure. The measurement of arbitrary devices under test is in excellent agreement with commercial measurement equipment and showed a mean deviation from the reference measurement of 0.17 dB and 1.29° regarding the forward transmission of a coaxial 30-dB attenuator. The system and receiver dynamic ranges are 44–77 and 82–101 dB at a resolution bandwidth of 100 kHz over the full system bandwidth. The measurements are highly repeatable and are robust against drift over time. As a proof of concept, the developed integrated network analyzers are utilized in a biomedical sensing scenario with an external and an on-chip sensor. Both approaches showed good sensitivity regarding the mixture ratio of binary solutions of ethanol and methanol. [ABSTRACT FROM PUBLISHER]

This work presents a chipset for a highly integrated heterodyne vector network analyzer (VNA) with two ports and a multi-octave bandwidth from 4 to 32 GHz. The chipset is comprised of a stimulus integrated circuit (IC) with two selectable single-ended output channels and a four-channel receiver IC. Both chips contain a frequency synthesizer with an average output power of 2.5 dBm and a single-sideband phase noise between -\96.3 and -\115.3 dBc/Hz at 1-MHz offset. The synthesizer consists of an array of three voltage-controlled oscillators with tuning ranges between 24.8% and 28.2% and a bandwidth extension stage. Wideband design techniques based on cascaded emitter followers are applied to a variable gain amplifier with a peak gain of 15.1 dB and to a wideband source switch with a minimum isolation of 23.6 dB. Single-ended receiver components such as a wideband low-noise amplifier with an average gain of 10 dB and a micromixer are used to compose the four-channel receiver with an average conversion gain of 14.4 dB. A hybrid microwave integrated circuit was fabricated in order to prove the functionality of a VNA utilizing the proposed chipset and wideband directional couplers. The measured scattering parameters of an arbitrary device-under-test showed an average deviation of 0.18 dB in magnitude and 1.8^\circ in phase from the measurements obtained with a commercial VNA. [ABSTRACT FROM PUBLISHER]