A 275 GHz Active Vector-Sum Phase Shifter

Abstract

Terahertz vector-sum phase shifters capable of 360 phase control over the frequency range of 240 to 310 GHz are presented. Because the impedance mismatch of the variable-gain amplifiers employed in the phase shifter determines the flatness of the offset phases, a new broadband VGA design with its input and output impedances unaffected by dc bias is introduced. The measured results on the phase shifter fabricated using 0.25 m InP HBT technology show incremental phase shifts of 45 with an average RMS offset phase error of 3.6 and insertion loss of to for eight basis dc bias states. Index Terms-InP HBT, phase shifter, terahertz IC, variablegain amplifier (VGA).

Hybrid 3-D-Printing Technology for Tunable THz Applications

“…At 110 GHz, McPherson et al [48] demonstrated an electronically tunable monolithic microwave integrated circuit (MMIC) in-phase/quadrature-phase (IQ) vector modulator, demonstrating 64-quaternary amplitude modulation (64-QAM) digital modulation directly at the carrier frequency, intended for implementing miniature softwarecontrolled transmitters. Recently, a 275-GHz MMIC phase shifter was reported by Quan et al [49], demonstrating a 360° phase shifter with 13-dB insertion loss over the 240-310-GHz frequency range. These MMIC solutions inherently suffer from high insertion loss and limited power handling capability [50], which may be critical factors for some applications.…”

Variable 360° Vector-Sum Phase Shifter With Coarse and Fine Vector Scaling

“…Design advances over the past decade have led to significant improvements in the fractional bandwidth of the phase shifters and a reduction in the footprint area of the chips. MMIC phase shifters covering the full 360°using different techniques, such as delay lines [1], [2], signal reflection [3], highpass/low-pass networks [4], all-pass networks [5], and vector summation [6]- [12].…”