Millimeter-wave (mm-wave) monolithic-microwave-integrated-circuit (MMIC) bandpass filters (BPFs) usually feature high insertion loss (IL). To this concern, an analytical method for low-loss MMIC BPFs is presented by using lumped-distributed parameters in this article. To reduce the IL, the enhanced-quality-factor resonator and low-loss coupling topology are both investigated. First, the proposed resonator and filter are realized by combining quasi-lumped elements and distributed mutual coupling. Both compact size and multiple transmission zeroes are accordingly realized. Second, a low-loss coupling topology is further introduced for MMIC filter by using mixed electric and magnetic couplings. For theoretical analysis, the lossy equivalent circuit modeling for mm-wave MMIC BPF is investigated, as well as an analytical parameter extraction. Based on the circuit analysis, a fast synthesis of low-loss mm-wave MMIC filter is presented. For demonstration, two compact MMIC BPFs are designed by using the gallium arsenide (GaAs) process. Low IL of only 0.95 dB, sharp rejection skirt of passband, and wide stopband are simultaneously obtained. The features of the proposed MMIC BPFs indicate promising applications in the fifth-generation (5G) mm-wave systems.

Low Insertion-Loss MMIC Bandpass Filter Using Lumped-Distributed Parameters for 5G Millimeter-Wave Application

A fully integrated 24-GHz Gilbert-cell mixer incorporating two on-chip Marchand baluns to convert single-ended signals into differential signals is presented in this paper. One is a passive balun at local oscillator (LO) port to improve isolation between the LO and radio-frequency (RF) ports, and the other is an active balun at RF port to enhance the conversion gain (CG) of the down-conversion mixer. The active balun utilizes complementary cross-coupled pairs (CCPs) to compensate for its resistive losses. Moreover, the gate-to-source capacitances ( $C_{{\text {gs}}}$ ) of the CCPs are also absorbed into coupled lines and then reduce the chip size. The chip area of the active balun is about one quarter of the passive one. The mixer is designed and implemented in a 0.18- $\mu \text{m}$ CMOS technology, and its chip size is 0.38 mm2 including all testing pads. With a power consumption of 18.9 mW and an LO power of 0 dBm, the mixer exhibits a measured CG of 12.8 dB, an input $P_{{\mathrm {in,1~dB}}}$ of −14.5 dBm, and LO-RF isolations better than 43 dB.

An Active Marchand Balun and Its Application to a 24-GHz CMOS Mixer

This paper presents a bandwidth-enhanced differential LC-Voltage Controlled Oscillator (LC-VCO) and varactor-coupled Quadrature VCO (QVCO) designed and simulated in high-performance SiGe HBTs of the GlobalFoundries (GFs) 130 nm SiGe BiCMOS8HP process for mmWave applications. Using the proposed varactor circuit, the designed VCO is operated in wideband and also the two-identical free-running differential VCOs (DVCOs) are coupled through the proposed varactor to oscillate in quadrature. The device sizes in the coupling network are properly set to achieve low I / Q errors. In addition, all the VCOs are designed in class-C to further improve their performances both in term of low power and low phase noise. The post-simulation results show that the differential oscillator is tunable from 20.3- to 31.3-GHz as the tuning voltage is varied from 0 to 1.2 V, while consuming only 10 mA from 1.2 V supply, presenting the best state-of-the-art figure-of-merit ( F o M T ) of −188 dBc/Hz. Similarly, the QVCO can cover 40.2 % oscillation bandwidth around 25.5 GHz oscillating frequency which is significantly wider than other state-of-the-art VCOs operating at comparable frequencies.

Bandwidth-enhanced differential VCO and varactor-coupled quadrature VCO for mmWave applications

Investigation of the self‐imaging position of a singlemode‐multimode‐singlemode optical fiber structure

This article presents the design, characterization, and modeling for the novel 3-D transformer structures based on the in-house developed 3-D integrated circuit (3-D IC) via-last backside-through-silicon via (TSV) interposer process. Differing from the conventional 2-D planar structure, the 3-D TSV design allows achieving a fully symmetric transformer with a compact size. The equivalent circuit model parameters are extracted based on the S-parameters to investigate the design tradeoff. With an inner diameter of $40~\mu \text{m}$ in the 3-D 1:1 transformer, the measured inductances of the primary and second coils are 439 and 482 pH with the $Q$ factors of 4.59 and 5.11, respectively, and the coupling coefficient is 0.136.

Fully Symmetric 3-D Transformers With Through-Silicon via IPD Technology for RF Applications

This paper presents a low-phase-noise and wide-tuning-range voltage-controlled oscillator (VCO) implemented in a standard 0.18- $\mu \text{m}$ complementary metal-oxide–semiconductor (CMOS) process with an integrated passive device (IPD) transformer. Even- and odd-mode oscillations of the transformer-based resonator can be achieved by the mode-switching topology, and the oscillations in the two modes result in a wide tuning range of the VCO. Moreover, the IPD-based transformer achieves high-quality ( $Q$ ) factors ( $Q >30$ ), which is impractical in standard CMOS-based technologies due to their lossy silicon substrate. The high- $Q$ IPD transformer reduces the phase noise of the VCO and, therefore, leads to a superior figure-of-merit (FOM) and FOM including the tuning range ( $\mathrm {FOM}_{T}$ ). Operating at 0.8 V supply voltage, the VCO consumes 9.2-mW dc power. At this bias condition, the measured phase noise is −124.2 dBc/Hz at 1-MHz offset from the 6.26-GHz oscillation frequency. Furthermore, the VCO exhibits a 65.7% tuning range and the flipped CMOS chip is packaged on the IPD substrate with a footprint area of 4.35 mm2. Compared with previously published CMOS-based VCOs, the presented VCO features excellent performances in phase noise, wide tuning range, FOM, and $\mathrm {FOM}_{T}$ .

Po-Hung Chen

Papers

A Low-Phase-Noise and Wide-Tuning-Range CMOS/IPD Transformer-Based VCO With High $\mathrm {FOM}_{T}$ of −206.8 dBc/Hz

An Active Marchand Balun and Its Application to a 24-GHz CMOS Mixer