Che-Chung Kuo

A 21 GHz Complementary Transformer Coupled CMOS VCO

A new topology for low power voltage controlled oscillators (VCOs) using a 0.18-mum CMOS foundry process is presented in this letter. From the measured results, the VCO exhibits a tuning range of 3% at 21.3 GHz. Using complementary topology, the core power consumption and the output power are 9.6 mW and -3 dBm, respectively. With the broadside coupled transformer, the VCO achieves a good phase noise of -106 dBc/Hz at 1 MHz offset and a compact chip size of 350 times 470 mum2. It is the first time that the broadside coupled transformer approach is applied to transformer coupled CMOS VCOs.

Novel Miniature and Broadband Millimeter-Wave Monolithic Star Mixers

In this paper, three monolithic star mixers using a new miniature dual balun are proposed. The first one is a double spiral transformer mixer, and the second one is a trifilar transformer mixer. Both of these are fabricated using a commercial GaAs pseudomorphic HEMT process. The third is a 3-D transformer mixer, which is fabricated using a commercial CMOS process. These mixers exhibit bandwidths over 25-45 GHz (57%) with local oscillator isolations better than 20 dB. These star mixers are smaller than (lambda/6timeslambda/6) for the mixer core area. Compared with traditional star mixers, these mixers demonstrate 80% size reduction, and achieve good performance with the smallest chip size among all star mixers using monolithic microwave integrated circuit processes.

A 10–35 GHz Low Power Bulk-DrivenMixer Using 0.13

10-35 GHz doubly balanced mixer using a 0.13-mum CMOS foundry process is presented in this letter. Using the bulk-driven topology, the number of transistors of the doubly balanced mixer is reduced; thus the mixer can achieve a low supply voltage and low power consumption. This bulk-driven mixer exhibits a measured conversion gain of -1 plusmn 2 dB from 10 to 35 GHz of radio frequency (RF) with a fixed intermediate frequency (IF) of 100 MHz. The measured local oscillation (LO) to IF and RF-IF isolations are better than 30 dB. The chip area of the mixer is 0.6 times 0.4 mm2. The total power consumption included output buffer is only 6 mW.

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In this paper, a fully system-in-package (SiP) integrated V-band Butler matrix beam-switching transmitter (TX) is presented. The CMOS chips from differential process technologies are assembled on a low-temperature co-fired ceramic (LTCC) substrate carrier by flip-chip interconnects. The vertically embedded folded monopole antenna is designed and integrated into the LTCC. The array consisting of four identical monopole antennas and a Butler matrix for beam switching is realized on the LTCC for loss reduction. Four switched main beams are measured and agree well with simulation. This beam-forming TX shows the potential of the low-cost millimeter-wave SiP with CMOS chips.

m CMOS Process

A K-band power amplifier that dynamically adjusts the dc consumption based on the output power is presented. Compared with a fixed-bias PA that consumes a constant dc power of 265 mW, the proposed PA saves 157 mW at quiescent state and 88 mW when operated at P1dB 6-dB back-off, and the OP1dB of the PA is also extended. This is the first CMOS PA with effective enhancement in back-off efficiency near MMW region.

A Fully SiP Integrated

A 40-GHz monolithic microwave integrated circuit (MMIC) single-pole-double-throw and multiple-port bandpass filter-integrated switches based on electronically switchable resonators are proposed. The proposed multifunction chip integrates a multiple-port switch with bandpass filter functions in a single chip. The switchable resonators are formed by quarter-wavelength stepped-impedance resonators with passive HEMT loading at one end. By properly allocating the resonant frequencies of the resonators in their on and off modes, a filter-integrated switch can perform a bandpass response with spurious suppression in the on state and achieve wideband isolation in the off state. The technique of using shared resonators is also introduced in the circuit design to reduce the overall circuit size. The results show the proposed circuits successfully integrate a MMIC switch with bandpass filter functions into a single circuit component.

V

A compact and broadband 15 to 50 GHz resistive FET ring mixer using 0.18-µm CMOS technology is presented in this letter. This mixer exhibits a conversion loss of 13–17 dB and the port to port isolations of better than 30 dB from 15–50 GHz for both down and up-conversion with a chip size of 0.2 mm2. Besides, this mixer has an input P1dB of 4–10 dB and an IF bandwidth of 5GHz. To the authors knowledge, this is the highest frequency MMIC resistive FET ring mixer using CMOS technologies to date.

-Band Butler Matrix End-Fire Beam-Switching Transmitter Using Flip-Chip Assembled CMOS Chips on LTCC

Two balance amplifiers operating at 2.5∼12-GHz with 1dB gain flatness and under 10 dB return loss are presented. Low loss broadband quadrature power splitters for BAs are realized on glass integrated passive device (GIPD) and low temperature cofired ceramic (LTCC). For 0.18-µm CMOS unit amplifier in BA, output matching network based on 3rd order band pass filter is used for optimum output power and good return loss. These BAs demonstrate widest bandwidth with smallest gain variation among power amplifiers under 15 GHz, and highest ratio of OP1dB to power stage transistor size is achieved on CMOS process.

K-band CMOS power amplifier with adaptive bias for enhancement in back-off efficiency

A K-band, 24 GHz, fully integrated transformer power amplifier (PA) is designed and fabricated in the standard 0.18-μm deep N-well (DNW) CMOS technology. This power amplifier is a 2-stage design using cascode RF NMOS configuration. The on-chip transformers are adopted for the power combining and impedance transformation for the matching network with a small size. The measurement results of this PA are linear gain of 15 dB, OP1dB of 18 dBm and PSAT of 23.5 dBm with power added efficiency (PAE) of 12%. Due to the small size of transformer, the size of the chip is only 0.86 × 0.56 mm2. To the authors knowledge, this PA not only demonstrates the highest output power among the CMOS PA in a 0.18-μm CMOS process, but also achieves the highest ratio of output power to chip size among the all reported K-band CMOS PAs.

40-GHz MMIC SPDT and Multiple-Port Bandpass Filter-Integrated Switches

In this paper, a reduced-size modulator with low LO power using a novel sub-harmonic mixer is presented. Compared to a conventional sub-harmonic mixer, this mixer is pumped by differential LO signals rather than quadrature LO signals. Therefore, the numbers of baluns, couplers, and mixing transistors used in this design are less than the ones used in a conventional modulator. The required LO power is also lower. This modulator demonstrates a measured conversion gain of -8 ~ -13.5 dB when RF frequency varies from 30 to 65 GHz with 4-dBm LO power. The chip size is 890 × 560 μm2 including pads.