Over 100 GHz millimeter-wave spectrum measurement system with pre-selector

Abstract

The recent start of R&D into Wireless Personal Networks (WPAN) and millimeter-wave wireless systems is creating an urgent need for development of a spectrum analyzer supporting accurate measurements in the frequency band above 100 GHz. However, there is no spectrum analyzer with a built-in pre-selector supporting spectrum analysis of wireless signals above 67 GHz. Such measurement is made generally by connecting a harmonic mixer or Block Down converter externally to a spectrum analyzer. In this case, generated unwanted signal components (spurious responses) are often seen during measurement, making it difficult to monitor the original signal components. This paper proposes development of a millimeter-wave spectrum measurement system incorporating a pre-selector function for wide dynamic range measurements with minimum unwanted signal components. We present the results of investigation into a prototype of the proposed system. We also measured a 120 GHz QPSK modulation wave to demonstrate the effectiveness of this system with pre-selector.

140–315 GHz spectrum measurement system and application to radiation pattern measurement

“…For this purpose, a filter, called a pre-selector, is placed in the first stage of the downconverter. We have previously realized waveguide-tunable filter as a pre-selector for a millimetre-wave spectrum measurement system above 100 GHz [2]. However, it was difficult to realize a tunable filter in the 300 GHz band, so we developed a filter bank.…”

Proposal of over 100-GHz Band Waveguide Switch

“…2 Tunable filter is a filter that can change central frequency of passband within its working range; the authors proposed FPW (Fabry-Perot resonator inside Waveguide) as a preselector for spectrum analyzers at frequencies over 100 GHz. 3,4 This filter features a wide frequency variable range, and can be realized as a compact device; however, there is a problem of great insertion loss due to the tuning mechanism. In addition, frequency tuning is performed by changing resonator length by an actuator, and requirements for actuator's position repeatability increase with higher frequency band, which poses another problem.…”

Proposal of over 100‐GHz band waveguide switch

“…There are 2 types of preselector–using tunable filters and filter banks, respectively . Tunable filter is a filter that can change central frequency of passband within its working range; the authors proposed FPW (Fabry‐Perot resonator inside Waveguide) as a preselector for spectrum analyzers at frequencies over 100 GHz . This filter features a wide frequency variable range, and can be realized as a compact device; however, there is a problem of great insertion loss due to the tuning mechanism.…”