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10 pages, 4418 KiB

Open AccessArticle

A 60 GHz Power Amplifier with Neutralization Capacitors and Compensation Inductors

by Joon-Hyung Kim and Chul-Woo Byeon

Electronics 2024, 13(21), 4276; https://doi.org/10.3390/electronics13214276 - 31 Oct 2024

Viewed by 624

In this paper, we present a high power-added efficiency (PAE) and high gain per stage 60 GHz power amplifier (PA). The proposed PA consists of a two-stage common-source amplifier that incorporates neutralization capacitors and compensation inductors to enhance both gain and efficiency. The [...] Read more.

In this paper, we present a high power-added efficiency (PAE) and high gain per stage 60 GHz power amplifier (PA). The proposed PA consists of a two-stage common-source amplifier that incorporates neutralization capacitors and compensation inductors to enhance both gain and efficiency. The gain characteristics are analyzed, demonstrating that the proposed design improves both gain and efficiency. Implemented in 65 nm CMOS technology, the PA achieves a saturated output power of 13.4 dBm at 60 GHz, with a maximum PAE of 26.7% from a 1 V supply. The output 1 dB compression point is 10.5 dBm, with a PAE of 16%. The PA occupies a core chip area of 0.094 mm². Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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19 pages, 11144 KiB

Open AccessArticle

Millimeter-Wave Choke Ring Antenna with Broad HPBW and Low Cross-Polarization for 28 GHz Dosimetry Studies

by Philip Ayiku Dzagbletey and Jae-Young Chung

Electronics 2024, 13(17), 3531; https://doi.org/10.3390/electronics13173531 - 5 Sep 2024

Viewed by 643

Abstract

A choke ring horn antenna has been designed for use as an RF applicator in a compact range in vitro 28 GHz bioelectromagnetic exposure system. The 30 mm × 50 mm horn antenna was fabricated and measured to operate from 27.75 GHz to [...] Read more.

A choke ring horn antenna has been designed for use as an RF applicator in a compact range in vitro 28 GHz bioelectromagnetic exposure system. The 30 mm × 50 mm horn antenna was fabricated and measured to operate from 27.75 GHz to 34.5 GHz with a −20 dB measured S11 and a measured antenna gain of more than 10 dBi. A wide sectoral (flat top) and symmetric E- and H-plane pattern with a half-power beamwidth of more than 60 degrees was achieved with a cross-polarization discrimination of better than 28 dB. Electromagnetic slots were introduced in the antenna to suppress excess cavity mode radiation which inherently impacts the cross-polarization levels of choke ring antennas. The proposed antenna was successfully integrated into the compact measurement chamber in partnership with the Korea Telecommunication Research Institute (ETRI) and is currently in use for real-time 5G millimeter-wave dosimetry studies. Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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13 pages, 441 KiB

Open AccessArticle

Multi-Link Prediction for mmWave Wireless Communication Systems Using Liquid Time-Constant Networks, Long Short- Term Memory, and Interpretation Using Symbolic Regression

by Vishnu S. Pendyala and Milind Patil

Electronics 2024, 13(14), 2736; https://doi.org/10.3390/electronics13142736 - 12 Jul 2024

Viewed by 2325

Abstract

A significant challenge encountered in mmWave and sub-terahertz systems used in 5G and the upcoming 6G networks is the rapid fluctuation in signal quality across various beam directions. Extremely high-frequency waves are highly vulnerable to obstruction, making even slight adjustments in device orientation [...] Read more.

A significant challenge encountered in mmWave and sub-terahertz systems used in 5G and the upcoming 6G networks is the rapid fluctuation in signal quality across various beam directions. Extremely high-frequency waves are highly vulnerable to obstruction, making even slight adjustments in device orientation or the presence of blockers capable of causing substantial fluctuations in link quality along a designated path. This issue poses a major obstacle because numerous applications with low-latency requirements necessitate the precise forecasting of network quality from many directions and cells. The method proposed in this research demonstrates an avant-garde approach for assessing the quality of multi-directional connections in mmWave systems by utilizing the Liquid Time-Constant network (LTC) instead of the conventionally used Long Short-Term Memory (LSTM) technique. The method’s validity was tested through an optimistic simulation involving monitoring multi-cell connections at 28 GHz in a scenario where humans and various obstructions were moving arbitrarily. The results with LTC are significantly better than those obtained by conventional approaches such as LSTM. The latter resulted in a test Root Mean Squared Error (RMSE) of 3.44 dB, while the former, 0.25 dB, demonstrating a 13-fold improvement. For better interpretability and to illustrate the complexity of prediction, an approximate mathematical expression is also fitted to the simulated signal data using Symbolic Regression. Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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12 pages, 3462 KiB

Open AccessArticle

Interstacked Transformer Quad-Core VCOs

by Daniele Tripoli, Giorgio Maiellaro, Santi Concetto Pavone and Egidio Ragonese

Electronics 2024, 13(5), 927; https://doi.org/10.3390/electronics13050927 - 29 Feb 2024

Cited by 1 | Viewed by 894

Abstract

This paper presents for the first time a quad-core oscillator based on a very compact interstacked transformer that tightly couples the four cores without oscillation mode ambiguity thanks to its strong magnetic coupling factor. As a proof of concept, a 19.125 GHz oscillator [...] Read more.

This paper presents for the first time a quad-core oscillator based on a very compact interstacked transformer that tightly couples the four cores without oscillation mode ambiguity thanks to its strong magnetic coupling factor. As a proof of concept, a 19.125 GHz oscillator for a narrowband 77 GHz radar system was designed in 28 nm fully depleted silicon-on-insulator CMOS technology with a general purpose back-end-of-line. The soundness of the proposed quad-core oscillator topology is demonstrated by comparison with state-of-the-art quad-core solutions, highlighting a significant advantage in terms of area occupation and power consumption. The proposed topology can be profitably exploited in several RF/mm-wave applications, such as radar and wireless communication systems. Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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17 pages, 10876 KiB

Open AccessArticle

Analysis and Optimization Design Scheme of CMOS Ultra-Wideband Reconfigurable Polyphase Filters on Mismatch and Voltage Loss

by Yingze Wang, Xiaoran Li, Yuanze Wang, Xinghua Wang, Zicheng Liu, Fang Han and Quanwen Qi

Electronics 2024, 13(3), 658; https://doi.org/10.3390/electronics13030658 - 5 Feb 2024

Viewed by 1144

Abstract

This manuscript presents an analysis and optimization scheme for the ultra-wideband passive reconfigurable polyphase filters (PPFs) to minimize I/Q (in-phase and quadrature-phase) phase/amplitude mismatch and voltage loss. By building a mathematical model of the voltage transfer, the relationship between the resonant frequency of [...] Read more.

This manuscript presents an analysis and optimization scheme for the ultra-wideband passive reconfigurable polyphase filters (PPFs) to minimize I/Q (in-phase and quadrature-phase) phase/amplitude mismatch and voltage loss. By building a mathematical model of the voltage transfer, the relationship between the resonant frequency of each stage and the I/Q mismatch and the relationship between the network impedance and the voltage loss are revealed, providing a scheme for PPF optimization. The proof-of-concept 2~8 GHz wideband reconfigurable PPF is designed in a 55 nm CMOS process. The optimization scheme enables the designed PPF to achieve an I/Q phase mismatch within 0.2439° and an I/Q amplitude mismatch within 0.098 dB throughout the entire band, and it shows great robustness during Monte Carlo sampling. The maximum voltage loss is 17.7 dB, and the total chip area is 0.174 × 0.145 mm². Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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17 pages, 8136 KiB

Open AccessArticle

A Miniaturized Bandpass Filter with Wideband and High Stopband Rejection Using LTCC Technology

by Yue Ma, Qifei Du, Wei Zhang, Cheng Liu and Hao Zhang

Electronics 2024, 13(1), 166; https://doi.org/10.3390/electronics13010166 - 29 Dec 2023

Viewed by 1400

Abstract

This paper designs an L-band wide stopband bandpass filter by applying low-temperature cofired ceramic (LTCC) technology to the global positioning system (GPS) frequency band. Taking the Chebyshev filter as a prototype, an equivalent collector element (capacitive and inductor) structure is adopted to fully [...] Read more.

This paper designs an L-band wide stopband bandpass filter by applying low-temperature cofired ceramic (LTCC) technology to the global positioning system (GPS) frequency band. Taking the Chebyshev filter as a prototype, an equivalent collector element (capacitive and inductor) structure is adopted to fully use the three-dimensional package structure of LTCC to reduce the filter size. The filter is integrated into an eight-layer LTCC dielectric, and the series–parallel connection of the collector elements in the resonance unit is utilized to produce out-of-band transmission zeros, while the input and output ports’ capacitance is adjusted to control the bandwidth. Harmonic suppression is achieved by cascading two new compact stopband filters, while the size increase is insignificant due to LTCC technology. The simulation results are as follows: the center frequency is 1.575 GHz, 1 dB relative bandwidth is 6.3%, insertion loss in the passband is as slight as 1.6 dB, return loss is better than 30 dB, rejection bandwidth up to 16 GHz is more than 44 dB, and the volume of the whole filter is 6.2 × 3.7 × 0.78

m m^{3}

. Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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9 pages, 3670 KiB

Open AccessCommunication

Time Domain Simulated Characterization of the Coplanar Waveguide in an On-Chip System for Millimeter Waveform Metrology

by Kejia Zhao, He Chen, Xiangjun Li, Jie Sun, Bo Li, Dexian Yan and Lanlan Li

Electronics 2024, 13(1), 145; https://doi.org/10.3390/electronics13010145 - 28 Dec 2023

Cited by 1 | Viewed by 883

Abstract

We investigate the time domain characterization of a coplanar waveguide (CPW) based on an on-chip electro-optic sampling (EOS) system for millimeter waveform metrology. The CPW is fabricated on a thin layer of low-temperature gallium arsenide (LT-GaAs), and the substrate material is GaAs. A [...] Read more.

We investigate the time domain characterization of a coplanar waveguide (CPW) based on an on-chip electro-optic sampling (EOS) system for millimeter waveform metrology. The CPW is fabricated on a thin layer of low-temperature gallium arsenide (LT-GaAs), and the substrate material is GaAs. A femtosecond laser generates and detects ultrashort pulses on the CPW. The forward propagating pulses are simulated using a simplified current source for the femtosecond laser at different positions on the CPW for the first time. Then, the influences of the CPW geometry parameters on the measured pulses are discussed. The varying slot width has larger influences on the amplitude of millimeter wave pulses than the center conductor width and the pumping gap. Finally, in the frequency range of 10 GHz to 500 GHz, the transfer functions calculated by the time domain pulses are in good agreement with the transfer functions calculated by the frequency domain ports. The above results are important for improving the measurement precision of the millimeter waveform on the CPW for millimeter waveform metrology. Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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11 pages, 7790 KiB

Open AccessCommunication

Design Techniques for L-C-L T-Type Wideband CMOS Phase Shifter with Suppressed Phase Error

by Seongjin Jang and Changkun Park

Electronics 2023, 12(20), 4368; https://doi.org/10.3390/electronics12204368 - 21 Oct 2023

Viewed by 1398

Abstract

In this study, we designed a K-band CMOS switch-type phase shifter. Equivalent circuits of shift and pass modes were analyzed to minimize phase errors in a wide frequency range. In particular, the impedance inside the equivalent circuit of the pass mode was analyzed [...] Read more.

In this study, we designed a K-band CMOS switch-type phase shifter. Equivalent circuits of shift and pass modes were analyzed to minimize phase errors in a wide frequency range. In particular, the impedance inside the equivalent circuit of the pass mode was analyzed to derive a frequency region in which the equivalent circuit of the pass mode becomes an L-C-L structure. Based on the fact that equivalent circuits in shift and pass modes can be regarded as L-C-L structures beyond a specific frequency, a design methodology of the wideband phase shifter was proposed through slope adjustment of the phase according to the frequency of each of the two modes. To verify the feasibility of the proposed design methodology, a 20°-bit phase shifter was designed through a 65 nm RFCMOS process. As a result of the measurement at 21.5 GHz to 40.0 GHz, the phase error was within 0.87°. Full article

(This article belongs to the Special Issue RF, Microwave, and Millimeter Wave Devices and Circuits and Their Applications)

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