Seigo Sano

A 500W Push-Pull AlGaN/GaN HEMT Amplifier for L-Band High Power Application

We have successfully developed a 500W AlGaN/GaN HEMT power amplifier with a frequency of 1.5GHz in L-Band, operating at 65V drain bias voltage. This amplifier consists of 4-chips of HEMT die developed for L-band frequency operation with push-pull configuration. The developed amplifier has an output power of 500W and a high linear gain of 17.8dB at the frequency of 1.5GHz under pulsed conditions at a duty of 10% with a pulse width of 100musec. To the best of our knowledge, this is the highest power ever reported for L-band GaN-related amplifier

A 80W 2-stage GaN HEMT Doherty Amplifier with 50dBc ACLR, 42% Efficiency 32dB Gain with DPD for W-CDMA Base station

A 2-stage 80 W amplifier, which consists of a 450 W saturated power GaN HEMT Doherty amplifier and a 30 W driver, was developed. At first we developed the 450 W GaN HEMT Doherty amplifier and obtained saturation power of 56.5 dBm(450 W) and drain efficiency of 55% at 6 dB back-off power showing typical Doherty amplifier behavior. Then we built the 2-stage amplifier up with the 30 W driver stage amplifier. With this amplifier we obtained 42% efficiency (including 30 W driver amplifier) and -50 dBc ACLR at the average power of 49 dBm(80 W) with saturation power of 56.5 dBm and Gain of 32 dB.

A kW-class AlGaN/GaN HEMT pallet amplifier for S-band high power application

We developed a kW-class AlGaN/GaN HEMT pallet amplifier operating at S-band. The pallet amplifier consists of an internally partial-matched AlGaN/GaN HEMT optimized for S-band on a copper base with soft PC boards. The developed pallet amplifier showed excellent performance, which is output power of over 800 W, high linear gain of 13.6dB and high efficiency of 52% over the wide frequency range of 2.9-3.3 GHz, operating at 65 V drain voltage with the pulsed condition at a duty of 10% and a pulse width of 200 musec. With 80 V drain voltage operation the peak power reached to 1 kW with 49.5% drain efficiency and 14.1 dB linear gain at 3.2 GHz. To the best of our knowledge, this is the highest power pallet amplifier ever reported for S-band.

A 45% Drain Efficiency, -50dBc ACLR GaN HEMT Class-E Amplifier with DPD for W-CDMA Base Station

A 10W GaN HEMT class-E amplifier for W-CDMA base station is demonstrated in this paper. We first demonstrate that a low pass type class-E circuit has quite similar performance to widely used series L-C resonance class-E circuit by simulating voltage and current waveforms with 50V operation GaN HEMT at 2.1GHz. We achieved measurement results; drain efficiency of 82%, CW output power of 11W and linear gain of 19.5dB at 2.1GHz and 50V drain bias operation with a simple low pass class-E circuit. And ACLR of -50dBc was obtained with 45% drain efficiency under 2-carrier W-CDMA , 7.8dB PAR (0.01%) signals, by using digital pre-distortion (DPD) operation

High temperature operation of AlGaN/GaN HEMT

We investigated high temperature operation of AlGaN/GaN HEMTs. At channel temperature of 269 degC, a linear gain of 12.3 dB and a power added efficiency of 53.6% were achieved at 2.14 GHz, less than 50 V operations. These are sufficient performance to practical application. At channel temperature of 368 degC, the linear gain was 10.4 dB and a power added efficiency of 43.9% was achieved. We also investigated the temperature dependence of equivalent circuit values, and found that the temperature dependence of saturated output power and the linear gain is originated from the temperature dependence of electron velocity in the channel.

A 100 W high-efficiency GaN HEMT amplifier for S-band wireless system

We have successfully developed a 100 W AlGaN/GaN power amplifier with a bandwidth of 300 MHz in S-band, operating at 50 V drain bias voltage. This amplifier consists of one HEMT die developed for L/S-band frequency operation and a single-ended package. The developed amplifier has an output power of 100 W and a high linear gain of more than 13.5 dB in the frequency range of 2.6 GHz to 2.9 GHz under CW or pulsed conditions [200 usec (pulse width) and 2 msec (period)]. High drain efficiency of 58% was also achieved at an output power of 100 W and frequency of 2.8 GHz. To the best of our knowledge this is the first report of 100 W AlGaN/GaN HEMT amplifier developed for S-band high power application.

A 65 % drain efficiency GaN HEMT with 200 W peak power for 20 V to 65 V envelope tracking base station amplifier

A 200 W GaN high electron mobility transistor (HEMT) device was developed for envelope tracking (ET) base station amplifier. The device, which consists of a single die of 0.6 um-gate GaN HEMT of 43 mm gate periphery, has a saturated current of 680 mA/mm together with sufficiently high break down voltage of 300 V. We have estimated the average power efficiency of ET amplifier by using the GaN HEMT device over 20 V to 65 V drain bias range. As a result, the estimated average power efficiency reaches at 65.2%. Excellent results of RF high temperature operating life (RF-HTOL) test were also obtained. To the best of our knowledge, this is the highest drain voltage operation of the GaN HEMT device, allowing significant improvement of efficiency for ET amplifiers.

A 9.5–10.5GHz 60W AlGaN/GaN HEMT for X-band high power application

In this paper, we report our result of a 60W AlGaN/GaN HEMT with the operating frequency in X-band. The device technology is extension of well-established Eudyna commercial L-/S-band AlGaN/GaN HEMT technology. The device shows output power of over 60W and a high linear gain of 9.6dB in wide frequency range of 9.5-10.5GHz, operating at 40 V drain bias voltage with the pulsed conditions at a duty of 10% with a pulse width of 100 musec. The results show the developed 60W AlGaN/GaN HEMT has high power capability covering practical frequency range for X-band high power applications with proven device technology.

High-efficiency and wide-band single-ended 200W GaN HEMT power amplifier for 2.1 GHz W-CDMA base station application

In this paper, we present high drain efficiency of 34% and wide-band characteristics of single-ended 200W GaN HEMT power amplifier for 2.1 GHz W-CDMA application. We also confirmed that GaN HEMT power amplifier has low memory effect and adjacent channel leakage power ratio (A.C.L.R.) is sufficiently reduced for the application by utilizing digital predistortion (D.P.D.) system.

An 8.5–10.0 GHz 310 W GaN HEMT for radar applications

A high-output power and broadband GaN high electron mobility transistor (HEMT) has been developed for X-band applications. The device consists of 2-dice of 14.4-mm gate periphery together with input and output 2-stage impedance transformers. The device exhibited saturated output power of 310 W with power gain of 10.0 dB over the wide frequency range of 8.5-10.0 GHz, operating at 65 V drain voltage under pulsed condition. In addition, the highest saturated output power reached 333 W with power gain of 10.2 dB at 9.0 GHz. This is the highest output power GaN HEMT ever reported for X-band.