This paper proposes a filtering matching network optimization design method using the fragment-type structure for continuous inverse class-F (CCF-1) power amplifier (PA). Different from the conventional microstrip matching structure, the fragment-type structure is used to increase the flexibility of optimization for a sharp roll-off at the second harmonic band. By using a multi-objective evolutionary algorithm, a filtering output matching network (OMN) with the fast transition between the passband and stopband is designed and optimized. For verification, a 1.5-3GHz broadband CCF-1 PA is designed, simulated and measured. Simulated results show that, compared with conventional Chebyshev filtering OMN design, the operational bandwidth of the proposed design can be expanded by about 15%. Experimental results show that measured efficiency of 65%-77% with a corresponding output power of 40.2-42.2dBm over a fractional bandwidth of 66.7% can be achieved.
Due to the advantages of good thermal and electrical performance, lower cost, greater design flexibility, fan-out wafer-level package (FOWLP) has been widely used in millimeter-wave applications. In this letter, a fan-out wafer-level package with the size of 12mm×12mm for the millimeter-wave applications is accomplished by the redistribution layer first (RDL-First) process. The double-sided multiple redistribution layers (RDLs) are used to fan out the signals and to form the antenna-in-package (AiP). An antenna integration scheme for the Ultra Short Range automotive Radar (USRR) chips with four transmit and receive channels was achieved. In addition, a 1×3 series fed aperture-coupled antenna array in the fan-out area was designed. Correspondingly, a probe based antenna measurement setup for FOWLP-AiP working in E band was carried out. The measurement results are in good agreement with the simulation.
Frequency-modulated continuous-wave (FMCW) radars necessitate fast frequency modulation. However, finite loop bandwidth of a phase-locked loop (PLL) limits the accuracy of fast frequency modulation. This paper proposes a phase compensation (PC) technique to address this limitation. The synthesizer PLL with the PC technique realizes fast and precise triangular chirp modulation by adding a compensating square wave phase before the integral path of the loop filter. The synthesizer is designed in 130-nm SiGe BiCMOS technology. Simulation results show rms frequency error improvement of 18 times over conventional PLL with a chirp bandwidth of 2.56GHz and 20µs chirp period at 94GHz.
An ultra-wideband (UWB) antenna with butterfly-like coupling slot for 4-element multiple-input multiple-output (MIMO) applications is introduced in this letter. In the design of the UWB antenna unit, the proposed butterfly-like slot is adopted to improve the impedance matching and achieves the operating bandwidth of 3-12GHz. At the same time, a symmetrical T-shaped meandering strip etched on the ground and connecting with the patch through via produces a notch at 5.1-5.37GHz, which suppresses the signal interference in WLAN band simultaneously. The results show that the proposed antenna array consisting of four orthogonal elements realized good isolation of lower than -15dB without any additional decoupled structures. Also, the proposed 2×2 MIMO design exhibited good diversity performance in terms of envelop correction coefficient (ECC<0.015), diversity gain (DG>9.92dB). The gain reaches a maximum value of 6.8dBi. Simulated and Measured results are in good accordance. All of this reveals the effectiveness of the proposed antenna in MIMO system and it can be suggested as a suitable candidate for UWB applications.
Microwave energy devices can coagulate biological tissues without generating surgical smoke. Therefore, we proposed the double-loop antenna for miniaturization and generating a localized heating to adapt microwave energy device for robotic surgery. The double-loop antenna consists of a double-loop and rod for changing the total antenna length. In order to evaluate the heating characteristics of our proposed antenna, the current distribution was calculated. As a result, it is confirmed that the combination of the double-loop and 10mm rod can achieve uniform heating.
A 2.58THz detector based on plasma-wave theory proposed by Dyakonov and Shur was designed and fabricated in 55nm standard CMOS process. Each detector consists of a filter patch antenna and a metal-oxide-semiconductor field-effect-transistor (MOSFET). We design a filter antenna to receive the terahertz signal, and the output of detector is extracted by a phase-locked amplifier. The antenna generates filtering function by adding two pairs of branches to the feeding lines. The frequency selection function of high spectral resolution detector proposed in this paper is mainly realized by filtering antenna. According to the test results and HFSS simulation results, the proposed filter antenna is feasible. The detector can achieve a room-temperature maximum responsivity (RV) of 67.2V/W. Our results show that CMOS terahertz detectors have potential applications in the imaging field.
This paper presents a multi-octave class-EFJ power amplifier based on a compact coupling structure. The compact coupling structure derives the output matching network impedance which is a simplified T-type network. The compact coupling structure reduces the output matching impedance range to meet the impedance requirement of the class-EFJ power amplifier. This coupling structure can meet the design space of the optimal fundamental impedance and control the harmonic matching impedance. Compared with the traditional design method, this design method can meet the requirement of the miniaturization and improve the efficiency in a wide bandwidth. In order to improve the efficiency and broaden the bandwidth, the input matching network is used a stepped impedance and open circuit microwave line matching method. To verify the proposed structure effectiveness, a multi-octave bandwidth and high efficiency PA is designed and fabricated with a GaN HEMT CGH40010F. The measured results show that the output power of 40.2dBm to 42.9dBm and the drain efficiency of 62.8%-72.4% are achieved at 0.9GHz-3.4GHz, respectively.
In order to solve the problems of slow speed and low accuracy of current screening of lithium batteries with different performance., a fast screening method for lithium batteries was proposed based on the second derivative of capacity-voltage discharge curve, and the 3.4V voltage point was taken as the feature point for screening. This method is faster than the traditional method, and the accuracy can be improved to more than 90%; In order to solve the problem of overcharging and other imbalance in lithium battery charging, a multi-mode serial-parallel conversion circuit was proposed, which takes 3.4V as the starting voltage of charge control, which can effectively equalize the charge of battery pack and eliminate the inconsistencies between batteries. After equalization charging, the voltage difference between battery packs can be reduced to less than 1mV.