Wafer-Level Amplitude Equalizer Based on an Integrated Passive Device Process with Two Resonance Points for Wavy In-Band Transmission

Amplitude equalizers play an important role in microwave transmission systems, and their performance can directly improve the signal transmission quality. Nowadays, the miniaturized equalizer is in good need of a highly integrated radio frequency (RF) front end. In this paper, a wafer-level amplitude equalizer based on an integrated passive device (IPD) process is proposed. Moreover, the equalizer circuit containing two resonance points within the transmission frequency band is also proposed. The amplitude equalizer operates at the center frequency of 3.88 GHz, with two resonance points of 2.9 GHz and 5.2 GHz; the minimum insertion loss is 1.17 dB, the maximum attenuation is 4 dB, and the in-band voltage standing wave ratio (VSWR) is less than 1.6:1. All the measured results are in good agreement with the designed results. The size of the proposed equalizer is 0.8 mm × 0.65 mm × 0.1 mm (0.011λ × 0.008λ × 0.001λ), which shows great potential in the miniaturization application of the RF microsystem. Furthermore, the new equalizer circuit with two resonance points is especially suitable for wavy in-band transmission.