A Tunable SiGe BiCMOS Gain-Equalizer For X-Band Phased-Array RADAR Applications

Abstract

This paper presents a compact-size tunable gainequalizer for X-Band Phased-Array RADAR applications in a 0.25µm SiGe BiCMOS technology. An isolated NMOS based variable resistance was used for the first time to tune the slope of the gain-equalizer. For NMOS, an isolated body created by a deep n-well was utilized to reduce insertion loss due to the substrate conductivity. Furthermore, the power-handling capability of the tunable gain-equalizer was improved thanks to the resistive bodyfloating technique. The designed tunable gain-equalizer operates in the frequency range from 8 to 12.5 GHz with a measured positive slope of 1 dB/GHz and 1 dB tunable slope. The effective chip area excluding the pads is 0.21 mm 2 , and the total area including pads is 0.31 mm 2. To authors best knowledge, this study is the first tunable gain-equalizer in SiGe technology presented for X-band phased-array RADAR applications.

Electrically tunable substrate integrated waveguide equalizer based on PIN diodes

“…Table 2 shows the comparison with other equalizers, which indicates the equalizer has better adaptability and flexibility in this work. Compared with previous studies, [2][3][4][5][6][7][8][9][10][11][12][13][14][15] SIW equalizer in this work combines many advantages simultaneously: continuous adjustment (not fixed ones and finite states), wider bandwidth, higher operating frequencies (theoretically only limited by characteristics of PIN diodes), a larger range of equalizing value, and low cost.…”

“…Until now, there have been numerous reports about equalizers. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] For example, in Tang et al, 2 an equalizer utilizing a spiral resonator was designed, and the experimental results presented an equalizing value of approximately 7 dB within the frequency range of 4-8 GHz. In Zhou and colleagues, [3][4][5] three broadband equalizers, based on the ceramic substrate or Rogers 5880, have been proposed.…”

“…Until now, there have been numerous reports about equalizers 2–15 . For example, in Tang et al, 2 an equalizer utilizing a spiral resonator was designed, and the experimental results presented an equalizing value of approximately 7 dB within the frequency range of 4–8 GHz.…”

“…It is worth noting that it is similar to a digital equalizer with minority combinations, rather than a continuous one. In Turkmen et al, 14 an isolated nMOS‐based variable resistance is used to tune the slope of gain‐equalizer with a measured positive slope of 1 dB/GHz and 1 dB tunable slope. In Song et al, 15 a tunable millimeter‐wave equalizer is presented, which is mainly composed of a microstrip through line and folded substrate integrated waveguide (FSIW) resonant cavities.…”