Youngoo Yang’s research while affiliated with Sungkyunkwan University and other places

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Publications (296)


Figure 1. Block diagram of diverse RF front-end for 5G/4G Application.
Figure 2. Proposed Low Noise Amplifier structure.
Performance by gain mode (@ 2.3~2.69 GHz).
Performance summary.
A 0.73 dB Multi-Gain Low Noise Amplifier Design with Fast Mode-Switching for 5G/4G Applications
  • Article
  • Full-text available

December 2024

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9 Reads

Sensors

Kyung-Duk Choi

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SungHwan Paik

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Kyung-Jin Lee

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[...]

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Kang-Yoon Lee

In this paper, a sub-1dB Low Noise Amplifier (LNA) with several gain modes, including amplification and attenuation modes required for the fifth and fourth generations (5G/4G) of mobile network applications, is proposed. Its current consumption is adaptive for every gain mode and varies to lower currents for lower amplifications due to the importance of current consumption for mobile network applications. The proposed LNA features an innovative architecture with a three-core input structure supporting multi-gain modes, achieving high gain and ultra-low noise performance. Additionally, the design integrates a cascade switching mechanism to ensure fast transitions between the gain modes and maintain operational stability. A reconfigurable input structure is introduced to support multiple input stages, enabling the proposed LNA to be compatible with both 5G and 4G applications. The proposed design demonstrates the implementation of seven distinct gain modes with a maximum current consumption of 11.68 mA, achieving proper input matching in each gain mode. The LNA delivers a maximum gain of 20.4 dB with a noise figure of 0.73 dB. Moreover, the most stringent mode switching condition achieved, the ON time, is as short as 1.295 µs, and the gain mode transition speed is an impressive 0.874 µs, ensuring extremely fast mode transitions. The proposed LNA occupies an area of 700 µm × 500 µm and is fabricated using a 65 nm FD-SOI process.

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23.5–27.5 GHz Band Doherty Power Amplifier Integrated Circuit Using 28 nm Bulk CMOS Process Based on Dynamic Power Dividing Network

October 2024

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39 Reads

Electronics

This paper presents a Doherty power amplifier (DPA) integrated circuit (IC) designed to have enhanced gain, efficiency, and AM-AM characteristics through a dynamic power dividing technique, which can control the power dividing ratio according to the input power. Since this multi-purpose dynamic power dividing network also provides the phase offset and impedance matching at the interstage network needed for appropriate DPA operation, the active IC area could be reduced. To verify the proposed technique and its analysis, the DPA was implemented with a 28 nm bulk CMOS process for the fifth-generation (5G) new radio (NR) millimeter-wave frequency band of 23.5–27.5 GHz. The measured results showed a gain of 20.3–21.9 dB, saturated output power of 14.0–15.2 dBm, power added efficiency (PAE) of 22.8–26.7% at the peak power, and PAE of 14.6–17.6% at the 6 dB output power back-off (OBO).




Fig. 4. The simulated FBWs for the four cases of the resonance circuit according to the electrical length of the series transmission line: (a) ZC,low, (b) ZC,peak, and (c) ZP,peak.
Fig. 7. Photograph of the fabricated DPA.
Fig. 9. Measured performances using a 5G NR signal with signal bandwidth of 100 MHz and a PAPR of 7.86 dB: (a) gain and DE without IDCC, (b) gain and DE with IDCC, (c) ACLR without IDCC, and (d) ACLR with IDCC.
Performance summary compared to previous studies
Bandwidth Extension of the Doherty Power Amplifier Using the Impedance Distribution and Control Circuit for the Post-Matching Network

July 2024

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15 Reads

Journal of Electromagnetic Engineering and Science

Owing to the high impedance transformation ratio, the Doherty power amplifier (DPA) with a large output power back-off generally has bandwidth limitations. This study proposes an asymmetric DPA with an impedance distribution and control circuit (IDCC) at the post-matching network to improve the bandwidth. The IDCC, based on a resonance circuit and a series transmission line, distributes and controls the load impedance according to the frequency so that the bandwidth of the DPA can be extended. To verify the proposed IDCC, an asymmetric DPA was designed using GaN HEMT with a power capacity of 6 W and 10 W for the carrier and peaking amplifiers, respectively. The implemented DPA was evaluated for the broad frequency band between 3.3 GHz and 3.8 GHz using a 5G new radio (NR) signal with a bandwidth of 100 MHz and a peak-to-average power ratio of 7.8 dB. A drain efficiency between 43.2% and 50.7% and an adjacent channel leakage power ratio between –23.4 dBc and –27.3 dBc were achieved at an average power level that ranged between 33.5 dBm and 34.3 dBm.



Figure 1. Configuration of the proposed series-fed antennas: (a) beam-tilted antenna, (b) broadside antenna.
The measured impedance bandwidth, AR bandwidth, RHCP realized gain, HPBW, and AR 3-dB beamwidth of the proposed antennas at 5.84 GHz.
Comparison of the proposed antenna with the previous works.
Design of Series-Fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application

April 2024

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48 Reads

Applied Sciences

In response to the increasing deployment of unmanned aerial vehicles (UAVs) across various sectors, the demand for efficient microwave power transmission (MPT) systems for UAVs has become paramount. This study introduces series-fed circularly polarized (CP) and passively beam-tilted patch array antennas designed to enhance MPT in UAV applications, with the intention of addressing the needs related to extending flight times and improving operational efficiency. The radiating element of the proposed antennas employs the conventional model of the patch with truncated corners for CP operation, with transmission line lengths optimized for beam tilt to ensure precise energy transfer. Additionally, an open stub is integrated into the broadside series-fed antenna to improve impedance matching, which is crucial for maintaining signal integrity. The proposed design achieves right-hand circular polarization (RHCP) with an axial ratio (AR) below 3 dB across the operating band, indicative of its effectiveness in diverse UAV operational contexts. Prototypes of each proposed antenna were fabricated and measured according to the beam tilting angle. The measured RHCP realized gains of the proposed antennas are 14.59, 13.09, 13.07, and 10.71 dBic at the tilted angles of 0∘, 15∘, 30∘, and 45∘, respectively, at 5.84 GHz.


60 W Class-E/F 3 Switching Power Amplifier With an Improved Second Harmonic Distortion of −49 dBc

January 2024

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46 Reads

IEEE Access

This paper presents a Class-E/F 3 switching power amplifier (SPA) with reduced second harmonic leakage using parallel resonant circuit in series for the second harmonics. The proposed Class-E/F 3 SPA has a structure utilizing a series resonant circuit in shunt for the third harmonic, designed to function as a shunt capacitor for the fundamental, and an additional parallel resonant circuit for the second harmonic, designed to operate as a series inductor for the fundamental. Using the proposed scheme, a Class-E/F 3 SPA was designed and implemented for 6.78 MHz, and was evaluated with various supply voltages. It exhibited output power levels ranging from 10.26 to 59.98 W (40.11 to 47.78 dBm) with supply voltages ranging from 10 to 24 V. The efficiency was maintained at over 89.25%. Additionally, it demonstrated very low second and third harmonic distortion levels, each not exceeding -49.98 dBc, while the total harmonic distortion (THD) ranged from 1.54% to 2.15%.


Citations (68)


... 반면 advanced DPA라 불리는 VS(virtual stub), OCC(outphased current combining) 또는 CCL(complex combining load) 방식의 DPA들은 OMN의 임피던스 매칭에 complex load impedance를 사용하여 큰 load modulation을 얻음으 로써 OBO를 확장하기 때문에 asymmetric DPA의 한계점 을 극복할 수 있다 [4]∼ [6] . 하지만 symmetric 구조를 사용한 advanced DPA들은 Class-C peaking 증폭기의 상대적 출력 저하 때문에 load modulation이 위축되는 현상을 겪기 때 문에 [4]∼ [7] , 최근에는 asymmetric DPA와 advanced DPA를 모두 사용한 연구들이 진행되었다 [8], [9] . ...

Reference:

Broadband Doherty Power Amplifier Using Out-Phased Current Combining Method and Asymmetric Cells
Broadband Virtual-Stub Doherty Power Amplifier Using Asymmetric Structure

IEEE Access

... S YNCHRONOUS boost converters find extensive applications in various systems such as photovoltaic (PV) systems [1], [2], [3], energy routers [4], [5], [6], electric vehicles (EVs) [7], [8], [9], uninterruptible power supplies (UPS) [10], [11], energy harvesting [12], [13], and battery-powered devices [14], [15], [16]. ...

A Design of Boost Converter With Time-Domain MPPT and Digital Self-Tracking ZCD for Thermoelectric Energy Harvesting Applications

IEEE Transactions on Power Electronics

... The need to maximize average efficiency, particularly for OBO ranging from 9 to 12 dB [1], calls for the extension of the existing solutions, such as the 6-dB two-way Doherty power amplifier (DPA) [2], or the development of new topologies such as the load-modulated balanced amplifier (LMBA) [3], distributed efficient power amplifier (DEPA) [4], and N -way DPA [5]. Even if a few examples extend toward high frequency [6], [7], [8], the prototypes presented in the literature mainly operate in the sub-6-GHz frequency bands and are based on single-stage demonstrators, achieving gains of the overall amplifier of the order of 10 dB. ...

A 6-/12-dB Back-off Multi-Mode GaN MMIC Doherty Power Amplifier for 5G Applications
  • Citing Conference Paper
  • June 2023

... A microwave coupler is a key component in wireless systems and is characterized by its bandwidth and size, among other parameters. In many emerging systems, such as multi-beam array antenna [1], Nolen/Butler/Blass matrix [2][3][4][5][6], frequency diverse array radar [7,8] or load modulated balanced amplifier [9], microwave couplers are required in large numbers, and their miniaturization can lead to a significant size reduction in the overall sensing systems, such as radars, LiDARs and other test equipment such as vector network analyzers and radio communication testers. ...

Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier

Journal of Electromagnetic Engineering and Science

... Reflector and array are examples of conventional high-gain antennas, but they have disadvantages such as a high geometric profile, difficulty achieving a flexible beam, and complex feeding networks [3]. Reflectarray antennas can overcome these limitations because they have a simple profile and low fabrication costs and are easy to deploy [4]. Reflectarray antennas are array antennas with a spatial feed [5]. ...

A Wideband Reflectarray Antenna for Satellite Application with Low Cross-Polarization

Applied Sciences

... Z C_in and Z P_in of Figure 1 represent the input impedances of the carrier and peaking amplifiers, respectively. The input impedance of the peaking amplifier, Z P_in , goes through a large transition while input power increases due to the nonlinear input capacitance, while Z C_in of the carrier amplifier has relatively small variation over the input power [3]. Therefore, the transition of Z P_in can be utilized to provide different power dividing ratios at the DPA low and peak power levels by controlling design parameters of the interstage transformer, phase offset, and the subsidiary impedance matching network. ...

Broadband InGaP/GaAs HBT Doherty Power Amplifier IC Using Direct Interstage Power Division for Compact 5G NR Handset Module

IEEE Access

... In 1935, William H. Doherty proposed a structure [16] that is still very popular because of its simplicity [42]. The main purpose of the proposed structure is that when the main amplifier is saturated, an auxiliary amplifier is added, and it causes the saturation to occur later, and the PA has been high efficiency from peak to back-off power levels [42][43][44][45][46][47][48][49][50][51][52][53][54]. ...

New Load Modulation Combiner Having a Capability of Back-Off Control for Doherty Power Amplifiers

IEEE Access

... To address the aforementioned issues, an improved and miniaturized mm-Wave 180 • out-of-phase SIW power divider based on an E-plane tee [17] is proposed and depicted in Figure 10(c). Energy is coupled from the WR-15 waveguide to SIW arms using two rectangular coupling patches printed within an aperture on the bottom metal layer. ...

Design of a Low-Cost, Low-Sidelobe-Level, Differential-Fed SIW Slot Array Antenna with Zero Beam Squint

Applied Sciences

... On the other hand, is greater than 1 as well; it is described by the size ratio of transistors MP4 and MP5 to create HYS− . Thereby, the values of HYS+ and HYS− can be calculated [18,19]: ...

A Design of Analog Front-End with DBPSK Demodulator for Magnetic Field Wireless Network Sensors

Sensors

... The maximum gain obtained is 19.1 dB, but the DC power consumption is not reported. A 28 nm CMOS transformer-based Doherty PA over a narrow frequency band from 23 to 28 GHz in Choi et al. [15], achieves a little power gain from 14 to 18.5 dB and a corresponding slight constant output power from 11.9 to 12.3 dBm. In Chen et al. [16], a 130 nm SiGe dual frequency band PA yields a mild power gain of 19.8 dB and 17.4 dB at 25 GHz and 35 GHz, respectively. ...

23-28 GHz Doherty Power Amplifier Using 28 nm CMOS for 5G Applications
  • Citing Conference Paper
  • August 2022