This paper presents three CMOS power amplifiers (PA) which realize wide-tunable output impedance matching. For realization of multi-standard and single-chip transceiver, the prototypes were fabricated by 0.18 µm CMOS process. The proposed PAs can achieve a tunable impedance matching within a wide frequency range by utilizing a resistive feedback and parallel resonator with an inductor and capacitor array. Therefore, the proposed PA has a realization possibility of isolator-less PA which contributes to decrease die area including external component. In other words, the PAs have tunable impedance matching function at their output ends. With a 3.3-V supply, three power amplifiers can cover frequency ranges of 0.9–3.0 GHz, 2.1–5.8 GHz, and 5.7–9.7 GHz, respectively. The PAs realize P1 dB of 21 dBm, Psat of 22 dBm, and PAEpeak of larger than 23%. The proposed PAs present a potential to realize multi-band transceivers without isolators.

We propose a synthesis and automatic layout method for mixed-signal circuits with high regularity. As the first step of this research, a resistive digital-to-analog converter (RDAC) is presented. With a size calculation routine, the area of this RDAC is minimized while satisfying the required matching precision without any optimization loops. We propose to partition the design into slices comprising of both analog and digital cells. These cells are programmed to be synthesized as similar as custom P-Cells based on the calculation above, and automatically laid out to form one slice cell. To synthesize digital circuits, without using digital standard cell library, we propose a versatile unit digital block consisting of 8 transistors. With one or several blocks, the transistors' interconnections are programmed in the units to realize various logic gates. By using this block, the slice shapes are aligned so that the layout space in between the slices are minimized. The proposed mixed-signal slice-based partition facilitates the place-and-route of the whole RDAC. The post-layout simulation shows that the generated 9-bit RDAC achieves 1GHz sampling frequency, -0.11/0.09 and -0.30/0.75 DNL and INL, respectively, 3.57mW power consumption, and 0.0038mm2 active area.

This article presents a 28GHz high-accuracy phase and amplitude detection circuit for dual-polarized phased-array calibration. With dual-polarized calibration scheme, external LO signal is not required for calibration. The proposed detection circuit detects phase and amplitude independently, using PDC and ADC. By utilizing a 28GHz-to-140kHz downconversion scheme, the phase and amplitude are detected more accurately. In addition, reference signal for PDC and ADC is generated from 28GHz LO signal with divide-by-6 dual-step-mixing injection locked frequency divider (ILFD). This ILFD achieves 24.5-32.5GHz (28%) locking range with only 3.0mW power consumption and 0.01mm2 area. In the measurement, the detection circuit achieves phase and amplitude detections with RMS errors of 0.17degree and 0.12dB, respectively. The total power consumption of the proposed circuit is 59mW with 1-V supply voltage.

This paper presents two CMOS power amplifiers which realize frequency band selection. Each PA consists of two stages and uses a transformer to obtain large output power with high efficiency. Furthermore, the capacitive cross-coupling at the second stage reduces a die area of the bypass capacitance. The proposed PAs are fabricated by a 0.18 µm CMOS process. With a 3.3 V supply, the PAs achieve a output 1-dB compression point of larger than 25 dBm from 2.2 GHz to 5.4 GHz, maximum of peak power added efficiency (PAEpeak) are 30% and 27% for 2-band and 3-band PAs, respectively. The proposed PAs have advantages which are a band-selectable ability within a desired frequency range and a realization of CMOS PA with high power efficiency.

In this paper, a capacitive-cross-coupling common-gate (CCC-CG) LNA using capacitive feedback is proposed to improve the noise figure (NF). In the conventional CCC-CG LNA, the transconductance gm is determined by the input-matching condition while a lager gm is required to improve NF. gm of the proposed LNA can be increased and NF can be improved by using the added capacitive feedback. The analytical calculation shows that the proposed LNA can perform better than the conventional CCC-CG LNA. In the measurement results using a 0.18-µm CMOS technology, the gain is 10.4–13.4 dB, NF is 2.7–2.9 dB at 0.8–1.8 GHz, and IIP3 is -7 dBm at 0.8 GHz. The power consumption is 6.5 mW with a 1.8-V supply.

In this paper, we propose a via distribution model for yield estimation. This model expresses a relationship between the number of vias and wire length. We also provide an estimate for the total number of vias in a circuit, derived from the via distribution and the wire-length distribution. The via distribution is modeled as a function of track utilization, and the wire-length distribution can be derived from the gate-level netlist and the layout area. We extract model parameters from the commercial chips designed for 0.18-µm and 0.13-µm CMOS processes, and demonstrate the yield degradation caused by vias.

In this paper, we propose a new Interconnect Length Distribution (ILD) model to evaluate X architecture. X architecture uses 45-wire orientations in addition to 90-wire orientations, which contributes to reduce the total wire length and the number of vias. In this paper, we evaluated interconnect length distribution of diagonal (45orientations) and all-directional wiring. The average length and the longest length of interconnect are estimated, and 18% reduction in power consumption and 17% improvement in clock frequency can be obtained by the diagonal wiring in the experimental results. The all-directional wiring does not have large advantage as compared the diagonal wiring.

The present paper proposes differential transmission line structures on Si ULSI. Interconnect structures are examined using numerical results from a two-dimensional electromagnetic simulation (Ansoft, 2D Extractor). The co-planar and diagonal-pair lines are found to have superior characteristics for gigahertz signal propagation through long interconnects. The proposed diagonal-pair line can reduce the crosstalk noise and interconnect resource concurrently.

In this paper we present eigenmode analysis of the propagation constant for a microstrip line with dummy fills on a Si CMOS substrate. The effect of dummy fills is not negligible, particularly in the millimeter-wave band, although it has been ignored below frequencies of a few GHz. The propagation constant of a microstrip line with a periodic structure on a Si CMOS substrate is analyzed by eigenmode analysis for one period of the line. The calculated propagation constant and characteristic impedance were compared with measured values for a chip fabricated by the 0.18 µm CMOS process. The agreement between the analysis and measurement was very good. The dependence of loss on the arrangement of dummy fills was also investigated by eigenmode analysis. It was found that the transmission loss becomes large when dummy fills are arranged at places where the electromagnetic field is strong.

This paper present a 20-GHz differential push-push voltage controlled oscillator (VCO) for 60-GHz frequency synthesizer. The 20-GHz VCO consists of a 10-GHz in-phase injection-coupled QVCO (IPIC-QVCO) with tail-filter and a differential output push-push doubler for 20-GHz output. The VCO fabricated in 65-nm CMOS technology, it achieves tuning range of 3 GHz from 17.5 GHz to 20.4 GHz with a phase noise of -113.8 dBc/Hz at 1 MHz offset. The core oscillator consumes up to 71 mW power and a FoM of -180.2 dBc/Hz is achieved.

A fully synthesizable all-digital phase-locked loop (AD-PLL) with a stochastic time-to-digital converter (STDC) is proposed in this paper. The whole AD-PLL circuit design is based on only standard cells from digital library, thus the layout of this AD-PLL can be automatically synthesized by a commercial place-and-route (P&R) tool with a foundry-provided standard-cell library. No manual layout and process modification is required in the whole AD-PLL design. In order to solve the delay mismatch issue in the delay-line-based time-to-digital converter (TDC), an STDC employing only standard D flip-flop (DFF) is presented to mitigate the sensitivity to layout mismatch resulted from automatic P&R. For the stochastic TDC, the key idea is to utilize the layout uncertainty due to automatic P&R which follows Gaussian distribution according to statistics theory. Moreover, the fully synthesized STDC can achieve a finer resolution compared to the conventional TDC. Implemented in a 28nm fully depleted silicon on insulator (FDSOI) technology, the fully synthesized PLL consumes only 480µW under 1.0V power supply while operating at 0.9GHz. It achieves a figure of merit (FoM) of -231.1dB with 4.0ps RMS jitter while occupying 0.0055mm2 chip area only.

This paper introduces a wireless-powered relay transceiver designed to extend 5G millimeter-wave coverage. It employs an on-chip butler matrix, enabling beam control-free operation. The prototype includes PCB array antennas and on-chip butler matrix and rectifiers manufactured using a Si CMOS 65 nm process. The relay transceiver performs effectively in beam angles from -45° to 45°. In the 24 GHz wireless power transmission (WPT) mode, it generates 0.12 mW with 0 dBm total input power, boasting an RF-DC conversion efficiency of 12.2%. It also demonstrates communication performance at 28 GHz in both RX and TX modes with a 100 MHz bandwidth and 64QAM modulation.

This paper presents a fully integrated yet compact receiver front-end for Sub-GHz applications such as Internet-of-Things (IoT). The low noise amplifier (LNA) matching network leverages an inductance boosting technique. A relatively small on-chip inductor with a compact area achieves impedance matching in such a low frequency. Moreover, a passive-mixer-first mode bypasses the LNA to extend the receiver dynamic-range. The passive mixer provides matching to the 50Ω antenna interface to eliminate the need for additional passive components. Therefore, the receiver can be fully-integrated without any off-chip matching components. The flipped-voltage-follower (FVF) cell is adopted in the low pass filter (LPF) and the variable gain amplifier (VGA) for its high linearity and low power consumption. Fabricated in 65nm LP CMOS process, the proposed receiver front-end occupies 0.37mm2 core area, with a tolerable input power ranging from -91.5dBm to -1dBm for 500kbps GMSK signal at 924MHz frequency. The power consumption is 1mW power under a 1.2V supply.

The variabilities of device characteristics are usually regarded as a normal distribution. If we consider the variabilities over the whole wafer, however, they cannot be expressed as a normal distribution due to the existence of global systematic component. We propose a statistical model, characterizing the global systematic component according to the distance from the center of the wafer, which can express the variabilities over the whole wafer statistically.

A 60-GHz CMOS transmitter with on-chip antenna for high-speed short-range wireless interconnections is presented. The radiation gain of the on-chip antenna is doubled using helium-3 ion irradiation technique. The transmitter core is composed of a resistive-feedback RF amplifier, a double-balanced passive mixer, and an injection-locked oscillator. The wideband and power-saving design of the transmitter core guarantees the low-power and high-data-rate characteristic. The transmitter fabricated in a 65-nm CMOS process achieves 5-Gb/s data rate with an EVM performance of $-$12 dB for BPSK modulation at a distance of 1,mm. The whole transmitter consumes 17,mW from a 1.2-V supply and occupies a core area of 0.64,mm$^{2}$ including the on-chip antenna. The gain-enhanced antenna together with the wideband and power-saving design of the transmitter provides a low-power low-cost full on-chip solution for the short-range high-data-rate wireless communication.

Regarding the enlarged array size for the 5G new radio (NR) millimeter-wave phased-array transceivers, an improved phase tuning resolution will be required to support the accurate beam control. This paper introduces a CMOS implementation of an active vector-summing phase shifter. The proposed phase shifter realizes a 6-bit phase shifting with an active area of 0.32mm2. To minimize the gain variation during the phase tuning, a gain error compensation technique is proposed. After the compensation, the measured gain variation within the 5G NR band n257 is less than 0.9dB. The corresponding RMS gain error is less than 0.2dB. The measured RMS phase error from 26.5GHz to 29.5GHz is less than 1.2°. Gain-invariant, high-resolution phase tuning is realized by this work. Considering the error vector magnitude (EVM) performance, the proposed phase shifter supports a maximum data rate of 11.2Gb/s in 256QAM with a power consumption of 25.2mW.

An energy efficient modulator for an ultra-low-power (ULP) 60-GHz IEEE transmitter is presented in this paper. The modulator consists of a differential duobinary coder and a semi-digital finite-impulse-response (FIR) pulse-shaping filter. By virtue of differential duobinary coding and pulse shaping, the transceiver successfully solves the adjacent-channel-power-ratio (ACPR) issue of conventional on-off-keying (OOK) transceivers. The proposed differential duobinary code adopts an over-sampling precoder, which relaxes timing requirement and reduces power consumption. The semi-digital FIR eliminates the power hungry digital multipliers and accumulators, and improves the power efficiency through optimization of filter parameters. Fabricated in a 65nm CMOS process, this modulator occupies a core area of 0.12mm2. With a throughput of 1.7Gbps/2.6Gbps, power consumption of modulator is 24.3mW/42.8mW respectively, while satisfying the IEEE 802.11ad spectrum mask.

This paper presents the evaluation of the L-2L de-embedding method with misalignment of the contact position. The issues of misalignment of the contact position are investigated. The analysis of misalignment in the L-2L de-embedding procedure is performed. Two comparisons are carried out to verify the error of the L-2L de-embedding method. The calculation percent error in quality factor of the transmission line becomes up to 9.0%, while the transistor S-parameter error percentage becomes up to 21% at 60 GHz in the experimental results. The results show that the measurement errors, caused by the misalignment of the contact position, should be considered carefully.

This paper presents a novel wide tuning range CMOS Voltage Controlled Oscillator (VCO). VCO uses an on-chip variable inductor as an additional variable element to extend the tuning range of VCO. The fabricated variable inductor achieves the variable range of 35%. The VCO was fabricated using 0.35 µm standard CMOS process, and can be tuned continuously from 2.13 GHz to 3.28 GHz (tuning range of 38%) without degradation of phase noise. Wide tunable LC-VCO using a variable inductor is one of the key circuits for reconfigurable RF circuit.