Ahmed Al Tanany

Broadband GaN switch mode class E power amplifier for UHF applications

In this work a broad-band class E power amplifier (PA) is designed, manufactured and measured. 400 MHz bandwidth with a center frequency of 800 MHz was realized using a GaN HEMT device. A novel and easy circuit topology is proposed for broad-band bandpass filter with integrated output matching network. Different filter types are discussed, suitable topology is chosen and design equations are shown. A maximum drain efficiency of 87.8 % (PAE = 80.6 %) is observed. Maximum output power of 49 W is measured with 16.3 dB power gain at the 1 dB compression point.

Analysis, Design, and Evaluation of LDMOS FETs for RF Power Applications up to 6 GHz

The analysis, design, and evaluation of medium-voltage laterally diffused metal oxide semiconductor (LDMOS) transistors for wireless applications up to 6 GHz is presented. Using an optimized N-LDMOS transistor, power devices of different transistor geometries were fabricated in a standard 0.25-μm bipolar complementary metal oxide semiconductor (BiCMOS) technology with and without on-chip stabilization networks. The influences of the finger geometry and the stabilization networks on the RF performance were studied based on small-signal and large-signal on-wafer measurements. It was analytically shown and experimentally verified that transistor geometries with reduced gate width per finger but higher number of fingers are advantageous regarding the maximum oscillation frequency. From the source/load-pull characterization of a 1.8-mm total gate-width device, state-of-the-art, large-signal performance with a maximum output power of 29.7 dBm and a peak drain efficiency of 44% were obtained at 5.8 GHz. Power evaluation of the LDMOS transistors was also carried out in designed hybrid power amplifier modules targeted for vehicular wireless LAN applications. In the 5.8-5.9 GHz band, an output power of 1 W at 1-dB power compression, an adjacent channel power ratio of -38 dBc and an error vector magnitude of 3% at 1 dB peak power compression are reported.

A 2.14 GHz 50 Watt 60% Power Added Efficiency GaN Current Mode Class D Power Amplifier

This paper presents a 50 W current mode class D (CMCD) power amplifier (PA) operating at 2.14 GHz. The PA is implemented using GaN pHEMT. The peak drain efficiency (iquest) is 62.7% and power added efficiency (PAE) is 60.3%. A resonator without an inductor was implemented to eliminate any loss that results from the low quality factors. The resonator uses narrow microstrip DC-feed lines located close to the drain leads which is used as resonator inductance. A model of the output capacitance (i.e.; Cds) was extracted from the die model and is used as a part of the resonator. Finally, a comparison between an ideal parallel LC with the proposed resonator was simulated to achieve the required impedance termination.

Design of Class F -1 Power Amplifier Using GaN pHEMT for Industrial Applications

This work presents a Class F-1 power amplifier (PA) operating at 2.35 GHz. An output power of 40 W (46 dBm) was achieved with 10 dB gain. The maximum drain efficiency was measured to be 60.8 % (PAE = 55.7 %). The power amplifier was implemented using GaN pHEMT. The realization of the optimum load resonator was designed by a microstrip resonator, for the first four harmonics. The resonator achieves an optimum load for the transistor at the fundamental frequency.

ANALYSIS OF BROADBAND GAN SWITCH MODE CLASS-E POWER AMPLIFIER

Switch mode power amplifiers offer high efficiency approaching 100 % for an ideal case. This paper discusses the operation mode of broadband switch mode class-E power amplifier designed previously by the authors for UHF applications (600 – 1000 MHz). A method to extract the waveforms at the die reference plane from the time domain analysis using 50 Ω environment system is discussed. It has been observed that the designed class-E power amplifier operation was not maintained ideally over the entire band, however, it was operating close to the class-E operation.