Ziliang Zhang

Ziliang Zhang

*This is an algorithmically generated author record based on publicly available information.

Ziliang Zhang has a total of 14 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • A 0.03 GHz to 6 GHz Gallium Nitride Monolithic Microwave Integrated Circuit Power Amplifier with Improved OIP3/Pdc Using Nonlinear Cancellation

    by Bowen Tang, Hui Jin, Ziliang Zhang, Chi Chen, Wenhao Zheng, Lei Huang, Yi Pei, Changchang Chen, Chun Wang, Yuehang Xu

    This study presents an ultra-wideband (UWB) and high-power amplifier (HP A) that employs a two-stage single-transistor driven distributed amplifier (SDDA) architecture to improve the linearity. The gate-bias optimization method for cascaded amplifiers is proposed based on nonlinear cancellation theory. By optimizing the bias and thereby changing the higher-order transconductance of transistors in the HP A, a third-order in-termodulation sweet spot (IM3-S) can be generated and shifted toward the saturation output region, which can improve the linearity with high output power and high efficiency in a UWB frequency. A monolithic microwave integrated circuit (MMIC) UWB-HP A was designed to validate the proposed method utilizing an in-house 0.25 µm gallium nitride (GaN) process. The SDDA demonstrates an output power exceeding 10 W across 0.03 GHz to 6 GHz and a power-added efficiency (P AE) greater than 41%. The two-tone measurement results indicate that, when the IM3-S is shifted to 0.9 dB output-back-off (OBO) at 2.6 GHz, the 1M3 reaches −33.8 dBc with an output power of 39.5 dBm and a P AE of 41%. At 5.6 GHz, after shifting the IM3-S to 2.2 dB OBO, the 1M3 reaches −35.6 dBc with an output power of 37.7 dBm and a PAE of 52%. The ratios of output third-order intercept point to direct current power (OIP3/Pdc) reach state-of-the-art values of 39 and 128 at 2.6 GHz and 5.6 GHz, respectively. The results of this study will be helpful for high linearity design of GaN UWB-HP As.


  • Open Access

    Internally Harmonic Matched Compact GaN Power Amplifier with 78.5% PAE for 2.45 GHz Wireless Power Transfer Systems

    by Caoyu Li, Ziliang Zhang, Yi Pei, Changchang Chen, Gang Feng, Yuehang Xu

    In this paper, a high-efficiency compact power amplifier is designed and fabricated with a 0.25 μm GaN high electron mobility transistor (HEMT) to meet the demands of a high integration level and high efficiency for microwave wireless power transfer (WPT) systems. The proposed power amplifier (PA) is implemented using an internally matched method to achieve a compact circuit size. The output second and third harmonic impedances can be optimized through output matching circuits, eliminating the need for additional harmonic matching networks. This approach simplifies the design of matching circuits and reduces the circuit size. Furthermore, the input third harmonic has been controled for improving the efficiency of DC-to-RF conversion. The total size of the proposed PA is 13.4 × 13.5 mm2. The test results obtained from the continuous wave (CW) testing indicate that the output power of the power amplifier at 2.45 GHz reaches 43.75 dBm. Additionally, the large-signal gain is measured at 15.75 dB, and the power-added efficiency (PAE) achieves a value of 78.5%.


  • Open Access

    Compact Internally Matched High-Power Power Amplifier with a Wide Frequency Band of 0.8–2 GHz

    by Caoyu Li, Ziliang Zhang, Xiang Su, Yue Li, Xinru Liang, Yi Pei, Changchang Chen, Yuehang Xu

    In this paper, a GaN high-electron-mobility transistor (HEMT) compact high-power wide-band power amplifier with an operation frequency from 0.8 GHz to 2 GHz is proposed. In order to realize a compact design, an internally matched method is employed. A wide-band matching strategy with an LC network and a multi-stage wide-band power combiner/divider is introduced in this design to achieve a wide bandwidth. A power combination structure is applied to have high output power. Wire-spiral inductance and film capacitors are employed to construct the compact matching network. The equivalent inductance of the bonding wire is also involved in the matching network. Experimental results show that the PAE (power-added efficiency) during the whole operation’s bandwidth (0.8 GHz to 2.0 GHz) is from 40% to 57%. The output power can reach from 48.3 dBm to 49.8 dBm with a circuit size of 30.8×27.4mm2.