These high-linearity power amplifiers provide cost-effective solutions to GaAs FET amplifiers in Wi-Fi and WiMAX wireless systems through 5.9 GHz.
Broadband wireless access (BWA) is being driven by increasing demand for streaming video and high-speed data anywhere and at any time. One of the technologies that may deliver these services is WiMAX, which has been standardized by the IEEE in both fixed and mobile formats. To power WiMAX transmitters at different frequencies, Sirenza Microdevices has developed a series of InGaP heterojunction-bipolar-transistor (HBT) power amplifiers with simple bias connections and flexible power control for applications from 2.2 through 5.9 GHz.
WiMAX applications call for a wide range of frequencies, since WiMAX standards have expanded to cover both fixed and mobile (moving) transmission and reception. WiMAX signals include both orthogonal frequency-division multiplex (OFDM) modulation for fixed systems and orthogonal frequency-division-multiple-access (OFDMA) signals for mobile systems. The Sirenza amplifier lineup addresses the full range of WiMAX frequencies in different product families.
The two current members of the SZP family, models SZP-2026Z and SZP-3026Z, consist of single-gain stages with input prematching, housed in low-cost SQF-26 surface-mount packages. Model SZP-2026Z operates from 2.2 to 2.7 GHz with 13.5 dB gain and +33.5 dBm output power at 1-dB compression. It draws 445 mA quiescent current from a single +5-VDC supply. Model SZP3026Z offers 11.5 dB gain from 3.3 to 3.8 GHz with +33.5 dBm output power at 1-dB compression. It draws 385 mA quiescent current from a single +5-VDC supply. The amplifiers include active bias circuitry for the simple positive-voltage supply connection. In addition, with only 7.5 dB of backoff from the 1dB compression point, both amplifiers can deliver+27 dBm output power at 2.5 percent error vector magnitude (EVM) when tested with a 64-state quadrature-amplitude-modulation (64QAM), OFDM modulation signal typical of those found in fixed WiMAX systems. Both amplifiers feature an on-chip power detector with a voltage-detection range of 0.9 to 2.2 V for power control.
For use with transmitter/receiver chip sets requiring somewhat higher small-signal gain, models SZM-2166Z and SZM-3166Z provide exceptional gain performance through 3.8 GHz. Model SZM-2166Z operates from 2.4 to 2.7 GHz with 34.5 dB gain and +33.5 dBm output power at 1-dB compression. It delivers +27 dBm output power at 2.5percent EVM and draws 655 mA quiescent current from a +6-VDC supply. It consumes 770 mA current when providing +27 dBm output power. Model SZM-3166P offers 34-dB small-signal gain from 3.3 to 3.8 GHz with +33.5dBm output power at 1-dB compression. It generates +27-dBm output power at 2.5-percent EVM while drawing 900 mA current from a single +5.2-VDC supply. The quiescent current is 600 mA from the same supply. Both high-gain amplifiers incorporate a 20-dB step attenuator (1-dB step control) for increased dynamic range and both are supplied in a 6 6-mm QFN package.
Model SZP-5026Z is the company's highest-frequency WiMAX amplifier, covering a range of 4.9 to 5.9 GHz. It provides 9 dB gain at 5.8 GHz and delivers 2 W (+33 dBm) output power at 1-dB compression. The output power is +26 dBm at 2.5-percent EVM (with an IEEE 802.11a 54-Mb/s signal). The amplifier draws 550 mA current from a +5-VDC supply when generating +26.5 dBm output power. The input return loss is 15 dB while the output return loss is 8 dB. The amplifier features flexible power up and down control with voltages of 3 to 5 V and less than 1 µs switching speed and on-chip bias circuitry, all packed into a SQF-26 housing.
Sirenza Microdevices, 303 South Technology Court, Broomfield, CO 80021; (303) 327-3030, FAX: (303) 410-7088, Internet: www.sirenza.com