370 W output power GaN-FET amplifier for W-CDMA cellular base stations

A single-ended amplifier using small packaged GaN-FETs exhibits a record 2.14 GHz W-CDMA output power. The amplifier, composed of paralleled 48 mm gate periphery FET die, delivers a peak saturated output power of 371 W with a linear gain of 11.2 dB at a drain voltage of 45 V under 2.14 GHz 3GPP W-CDMA signal input. The output power density (output power/package size) of 1.1 W/mm/sup 2/ is twice as high as that of the existing over 300 W GaAs-FET amplifiers. A low 5 MHz offset ACLR of -36 dBc with a drain efficiency of 24% is also obtained at 8 dB power back off from the saturated output power.     

A GaAs-based field-modulating plate HFET with improved WCDMA peak-output-power characteristics

A novel GaAs power FET with a field-modulating plate (FP-FET) and operated at a drain bias voltage of 24 V was developed. Regarding the power performance of an FP-FET under wideband code division multiple access (WCDMA) operation, its peak output power significantly degraded in the saturated-output-power region when its FP length was short. However, by introducing a sufficiently large FP length, it was demonstrated that the peak-power degradation can be significantly suppressed. In particular, an FP-FET amplifier fabricated with an FP length of 1.5 /spl mu/m exhibited no WCDMA peak-power degradation and delivered an output power of 120 W with a linear gain of 14.2 dB at 2.14 GHz.     

280 W output power single-ended amplifier using single-die GaN-FET for W-CDMA cellular base stations

A single-ended amplifier using a single-die GaN-FET was successfully developed for W-CDMA cellular base-station systems. The developed amplifier delivers a peak saturated output power of 280 W with a linear gain of 12.6 dB at a drain voltage of 48 V under 2.15 GHz 3GPP W-CDMA signal input. It is believed that the 280 W output power is the record output power in single-ended amplifiers at 2 GHz band. A high drain efficiency of 29% is also obtained at 8 dB power back off from the saturated output power.     

230W C-band GaN-FET power amplifier

A C-band high-power amplifier with two GaN-based FET chips exhibits record output powers under continuous-wave (CW) and pulsed operation conditions. At 5.0 GHz, the developed GaN-FET amplifier delivers a CW 208 W output power with 11.9 dB linear gain and 34% power-added efficiency. It also shows a pulsed 232 W output power with 8.3 dB linear gain.     

Pulsed 0.75kW output single-ended GaN-FET amplifier for L/S band applications

A pulsed 0.75 kW output GaN-FET amplifier for L/S band high power applications has been successfully developed. A single-ended configuration is adopted to make the amplifier compact and simple. The amplifier delivers a saturated output power of 0.75 kW under pulsed RF operation at 2.14 GHz, which is believed to be the highest output power reported in an L/S band single-packaged device     

C-band GaAs FET power amplifiers with 70-W output power and 50% PAE for satellite communication use

This paper describes a successfully developed high-power and high-efficiency C-band GaAs FET amplifier for satellite communication systems. To realize high efficiency in a high-power amplifier, an HFET well-designed for high-power applications is developed, and precise design for an amplifier is carried out. The HFET employed achieves reduction in a gate leakage current while maintaining a high maximum drain current. For precise design of an amplifier, large-signal FET model parameters are extracted using pulsed I-V and S-parameter measurements. Based on this model, second harmonic impedances as well as fundamental impedances are determined for obtaining high efficiency and input- and output-matching circuits which are assembled in a compact package are designed to achieve a high-efficiency internally matched amplifier. As a result, the amplifier delivers a high saturated output power of 70 W and a high power-added efficiency of 51%. These characteristics are the record power performance in C-band in terms of simultaneous achievement of high power and high efficiency. A low third order intermodulation distortion of -35 dBc is also obtained at a drain voltage of 10 V.     

InAlAs/InGaAs channel composition modulated transistors with InAschannel and AlAs/InAs superlattice barrier layer

We have successfully fabricated a new type of InAlAs/InGaAs heterojunction FET (HJFET) with modulated indium composition channels, called channel composition modulated transistors (CCMTs) in which an InAs channel is sandwiched by In_0.53Ga_0.47As/In _0.8Ga_0.2As sub-channels. The fabricated devices also employ an AlAs/InAs superlattice as a barrier layer against impurity contamination to provide high thermal stability. A 0.2-μm T-shaped gate device exhibits a g_m of 1370 mS/mm, F_t of 180 GHz and F_max of 210 GHz at a low drain bias of 1.0 V. In high-temperature DC life tests conducted at more than 230°C, the devices exhibited less than a 3% degradation in I_dss and g_m after 1000 h. This demonstrates that these newly-developed CCMTs incorporating AlAs/InAs superlattice insertion technology can offer high-performance and highly-reliable InP-based HJFET's for various microwave and millimeter-wave applications     

100 W C-band single-chip GaN FET power amplifier

A single-chip GaN-FET amplifier exhibits record output powers of C-band solid-state amplifiers under continuous-wave (CW) and pulsed operation conditions. At 5.0 GHz, the developed GaN-FET amplifier with 24 mm gate periphery delivered a CW 100 W output power with 12.9 dB linear gain and 31% power-added efficiency and a pulsed 155 W output power with 13.0 dB linear gain.