This letter proposes a novel broadband, high-efficiency power amplifier (PA). The high-efficiency characteristics of Class-EF PAs and the large bandwidth advantages of Class-J PAs are effectively combined in the proposed PA. By theoretically analyzing the impedances of traditional Class-EF PAs and class-J PAs, we can consider the possibility of combining these two types of PAs. The conditions that need to be met are derived. In order to verify the effectiveness of the proposed method, a high-efficiency wideband Class-EFJ PA is designed and fabricated by using CGH40010F GaN HEMT. The measurement results demonstrate that the Class-EFJ PA has saturated output power of 40.5-42.7 dBm in 1.2-3.6 GHz. Drain efficiency of 63%-73% was achieved over the same frequency band. The Adjacent Channel Leakage Ratio (ACLR) was also better than -31.2 dBc at an average output power of 35.6 dBm.

In this work, we study sensing-aided uplink transmission in an integrated sensing and communication (ISAC) vehicular network with the use of orthogonal time frequency space (OTFS) modulation. To exploit sensing parameters for improving uplink communications, the parameters must be first associated with the transmitters, which is a challenging task. We propose a scheme that jointly conducts parameter association, channel estimation and signal detection by formulating it as a constrained bilinear recovery problem. Then we develop a message passing algorithm to solve the problem, leveraging the bilinear unitary approximate message passing (Bi-UAMP) algorithm. Numerical results validate the proposed scheme, which show that relevant performance bounds can be closely approached.

This paper proposes a method that employs novel hybrid continuous class-EFJ power amplifiers (PAs) as carrier PA to design a broadband high-efficiency Doherty power amplifier (DPA). Bandwidth characteristic of the proposed DPA is analyzed in detail. By proper selection of related parameter values, up to 78% fabrication bandwidth can be obtained. Post-harmonic tuning network is applied to improve the bandwidth and enhance the efficiency. Then, a closed design process is presented to design broadband DPA based on derived theories. For validation, a broadband DPA operating in 1.2-2.8 GHz is designed and fabricated. Measurements illustrate that the DPA can deliver saturated output power between 43.7 dBm and 44.1 dBm in 1.2-2.8 GHz, and the saturated drain efficiency from 60.5% to 74.2 % is achieved. Moreover, drain efficiency is 48.1%-57.6% at the 6 dB power back-off. Compared with conventional DPAs, the proposed DPA exhibits superior performance of bandwidth characteristics and power back-off efficiency over a wide bandwidth.

An extended version of the continuous-mode Class-GF power amplifier (PA) design theory is first proposed in this letter by analyzing the impact of input voltage waveform alterations caused by input nonlinearity on the drain current waveform. Then, a novel impedance design space is explored under the extended continuous-mode drain voltage waveform. Thereafter, a multioctave, high-efficiency extended continuous Class-GF (ECCGF) PA component was implemented, fabricated, and measured with a 10-W GaN HEMT device over a 150% bandwidth from 0.4 to 2.8 GHz. The test result shows that the 39–42-dBm output power, 63%–73.2% drain efficiency (DE), and 9–12-dB gain are achieved in the target band.

This letter presents a simple method to design dual-band high-efficiency power amplifiers (PAs). The dual-band coupler is exploited to design the output circuits of the PA. By proper selection of impedance conditions of terminal ports, the dual-band coupler can convert the fundamental impedance of transistor to the standard 50-Ω load at two frequencies. At the same time, the second harmonic impedance is also controlled without the need for additional tuning. For validation, a dual-band high-efficiency PA is designed and fabricated by using CGH40010F GaN HEMT. Measurements indicate that the designed PA can deliver saturated output power of 41.6 and 42.1 dBm at 1 and 2.3 GHz, respectively. Also, the obtained drain efficiency exceeds 72% at both frequencies.

This letter proposes a dual-band high-efficiency rectifier using a GaN transistor. Positive polarity and negative polarity modes are set at $f_{1}$ , and $f_{2}$ , respectively. Then, the rectifier operation at $f_{1}$ and $f_{2}$ is realized upon adjusting only the phase of the corresponding feedback loop. This releases the limitation that the original power amplifier (PA) must be dual-band operation. In addition, class-F harmonic control theory is used to enhance efficiency. Moreover, the proposed technique has no frequency dependence and can be used to achieve arbitrary frequency ratios. To verify the effectiveness of the proposed method, a high-efficiency rectifier operating at 1.9 and 2.4 GHz is designed and fabricated using a CGH40010F GaN HEMT. Measurements illustrate that the implemented rectifier can realize an efficiency of over 75% at 1.9 GHz and 2.4 GHz when an input power of 40 dBm is applied and the dc load is $70~\Omega $ . Also, the size of circuit is only 4.7 cm $\times3.4$ cm.