A novel broadband MMIC vector modulator for V-band applications

Abstract

In this study, a new vector modulator topology is presented. The modulator is composed by two ''balanced-load'' biphase modulators. The balanced load is a novel principle allowing a topological simplification of commonly adopted vector modulator schemes: seven couplers are used instead of the 9 ones in traditional reflection-type modulators, with comparable performance. The measured results of monolithic 45-65 GHz test vehicles of the methodology for both biphase and vector modulators, are presented.

A Comparative Study of Single-Ended vs. Differential Six-Port Modulators for Wireless Communications

“…can only be zero when α 0 = α 2 = 0 and Ae jφ = 1/α 1 . Because the denominator of α 0 , α 1 and α 2 are dependent on the reflection coefficient, as seen from (16) - (18) and 22- (24), the condition Ae jφ = 1/α 1 cannot in general be fulfilled, which results in a small error. However, the variation in the denominator of α 0 , α 1 and α 2 with the reflection coefficient is assumed to be small around the design frequency, in which case the condition Ae jφ ≈ 1/α 1 can be achieved.…”

“…The variable impedance loads are used to generate different reflection coefficients on the respective ports of the six-port correlator, which in turn modulates an applied carrier signal [5], [8], [9], [18], [19]. The variable load can, for example, be implemented with transistors [10], [11], [18], [20], switches [5], [9] or diodes [12], [13]. As stated by Shannon and Nyquist, the key factors of communication are bandwidth, number of signal levels, and signal-to-noise ratio [15].…”

SiGe process integrated full‐360° microelectromechanical systems‐based active phase shifter for W‐band automotive radar

“…One such radar application area is at W-band automotive radar system where it is possible to have compact and high-speed radar with minimal interfering signals [1]. Several approaches have been taken to implement the phase shifters including: reflective type phase shifters [2,3], switched high pass/low pass phase shifters [4,5], vector modulator techniques [6,7] and vector-sum phase shifters [8][9][10][11][12][13][14][15][16]. Regarding available monolithic microwave integrated circuits (MMIC) technologies at high frequency, switched network phase shifters require large die size and incur high costs and reflection type phase shifters cannot be properly implemented because of parasitic effects [10].…”