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AH212 Reference Design
The first two power amplifier TD-SCDMA stages require a gain of 33dB. By utilizing the AH212 (25dB) and AP602/3 (12dB) combination, a 37dB of gain is realized, thus exceeding the TD-SCDMA requirement.
The AH212, InGaP/GaAs HBT is able to achieve superior performance for various narrowband-tuned application circuits with up to +46 dBm OIP3 and +30 dBm of compressed 1-dB power. The small form factor allows high level of integration resulting in 50% PCB space savings and 25% fewer tuning components, making it ideal for cellular base station and repeater designs.
Both AP602 and AP603 use the high reliability, high voltage InGaP/GaAs HBT process technology. These devices incorporate proprietary bias circuitry to compensate for variations in linearity and current draw over temperature. The AP602 is a dynamic single stage power amplifier provides excellent backoff linearity, while being able to achieve high performance for 800-2350 MHz applications with up to +35.7 dBm of compressed 1dB power. Similarly, AP603 is able to achieve high performance for 800-2350 MHz applications with up to +38.5 dBm of compressed 1dB power, along with excellent linearity.
AH212 Driver Amplifier for AP60x
2-chip Solution for TD-SCDMA Applications
The AH212 is an ideal amplifier for the entire AP60x series, meeting the system requirements. Here’s how
AP602 P1dB = 36dBm
AP602 Gain = 13dB
Rule of thumb calculation for P1dB of device to drive AP602 (for example)
Driver P1dB = (AP602 P1dB) – (AP602 Gain) + 3dB
= 36dBm – 13B + 3dB
= 26dBm
AH212 P1dB = 30dBm
Therefore, the above calculation proves that WJ’s AH212 is the most suitable driver amplifier for AP602. It can also be used to drive the AP603 device.
Summary
This 2-chip solution has proven successful in numerous applications in China. For more information on how the AH212 and AP602/3 combination can meet your TD-SCDMA application, please contact our China applications team at:
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