Characterization and thermal analysis of a 48 V GaN HFET device technology for wireless infrastructure applications
ABSTRACT This report presents the DC, pulsed I-V, small signal, and large signal characteristics of Freescalepsilas 48 V GaN HFET technology. Characterization of large signal performance for a 12.6 mm at 48 V drain bias shows 89 W output power with an associated power density of 7.1 W/mm, linear gain of 17.5 dB, and a power-added efficiency (PAE) of 62%. Analysis of channel temperature over drain bias shows that the maximum channel temperatures at 28 V and 48 V are 107 degC and 245 degC, respectively during saturated RF operation. Data for RF drift over time on a 16.2 mm device show less than 0.2 dB of RF drift for >1000 hrs. of testing. This level of RF performance represents a significant >4 dB gain and >2 W/mm power density improvement over Freescalepsilas previously reported GaN HFET technology.
Conference Proceeding: High Efficiency GaN HEMT Power Amplifier optimized for OFDM EER Transmitter[show abstract] [hide abstract]
ABSTRACT: We have proposed a highly efficient power amplifier (PA) for the envelope elimination and restoration (EER) transmitter using gallium nitride (GaN) HEMT. The class AB, B, C and F mode PAs have been implemented with EUDYNA's 10 watts GaN HEMT and compared the bias modulation performances in order to investigate the optimum PA structure. The proposed class F mode PA has been biased at class C and adopted a new output matching topology that improves the overall transmitter efficiency. For the WiMAX OFDM signal, the calculated overall drain efficiencies of the optimized EER amplifier, which are based on the measuremed bias dependent efficiencies, are about 73 % at an average power of 31 dBm at 2.14 GHz. The proposed highly efficient bias modulation PA for the EER transmitter provides a superior overall efficiency than that of any conventional switching or saturation mode PAs.Microwave Symposium, 2007. IEEE/MTT-S International; 07/2007
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ABSTRACT: A Class F amplifier has been designed, fabricated, and tested using a GaN HEMT transistor and hybrid printed circuit board (PCB) packaging. The amplifier has a peak power-added efficiency (PAE) of 85% with an output power of 16.5 W. A gate-connected field-plated and a source-connected field-plated device of the same size and layout were measured in this topology. An output power and drain efficiency tradeoff, dependant on the drain impedance at the fundamental frequency due to the on-state resistance, is explored. A comparison between Class F and Inverse F, given particular operating conditions for this device, is made.IEEE Journal of Solid-State Circuits 11/2007; · 3.06 Impact Factor
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ABSTRACT: This letter reports a high efficiency class-E power amplifier using a GaN high electron mobility transistor (HEMT), which is designed at WCDMA band of 2.14 GHz. To improve output power and efficiency by suppressing harmonic powers, an output network using transmission lines is used. For a single tone, the proposed output network suppresses all harmonic power levels below -60 dBc for the whole output power range. The peak power-added efficiency (PAE) of 70% with a power gain of 13 dB is achieved at an output power of 43 d Bin. The broadband performance with a power gain over 12 dB and PAE over 60% is maintained through 200 MHz.IEEE Microwave and Wireless Components Letters 09/2007; · 1.78 Impact Factor