Combining gallium arsenide (GaAs) power amplifier circuit with integrated passive devices (IPDs) and microvia high-density interconnect (HDI) technology, Freescale Semiconductor has crafted a power amplifier front-end module, labeled MMM6025, as part of its 2.5G innovative convergence product offering for quad- and tri-band GSM handsets. Other offerings in the convergence platform include quad-band GSM/GPRS front-end IC, integrated power management and audio circuit, baseband processor and charge control and protection ICs.

The MMM6025 is a 50 Ω transceiver power amplifier module for quad- and tri-band GSM handset applications, functioning over the GSM850, EGSM, DCS and PCS transmit and receive frequency bands. It is compatible with GSM/GPRS Class 12 operating modes. To simplify radio front-end design requirements, the MMM6025 module has integrated power amplification, power coupling, power detection, low-pass filtering, and antenna switching functions.

The MMM6025 uses a single chip gallium arsenide (GaAs) four-band RF power amplifier circuit, low-loss highly integrated passive devices (IPDs), SiGe power detection and antenna controller and a highly functional GaAs pseudomorphic high-electron mobility transistor (pHEMT) antenna switch to take advantage of its compact microvia substrate technology. Merging many of the critical valued RF capacitor, inductor and coupler functions into the IPDs significantly reduced the total number of in module components to offer a solution that is more efficient with smaller size and lower cost, stated Cliff Vaughan, Freescale's module methodologist.

The MMM6025 uses a single e-mode GaAs die that combines the two high- band (PCS and DCS) and low-band (EGSM and GSM-850) power amplifier functions with the appropriate bias and gain control. The low output impedance from the two GaAs power amplifiers is matched into precision power couplers to sample the forward RF energy into the antenna. This cellular transmit RF energy, now at 50 Ω, goes through the harmonic filters into a GaAs SP6T switch that directs it to the antenna port. This same switch functions as a four-band receiver switch to connect the module's antenna node to the appropriate receiver ports. Other features include small size, low profile of the 34-pin multichip RF module, high-resolution directional power detection (<+/1 dB power variation into 6:1VSWR antenna mismatch), high power efficiency, low receiver band noise, high ruggedness, high stability and an operating temperature range of -20° to +70° C.

Furthermore, minimum power out at nominal voltage (3.2 V) is 33 dBm with 43% ( typical) power-added efficiency (PAE) for GSM-850, 33 dBm with 43% (typical) PAE for EGSM, 30 dBm with 35% (typical) PAE for DCS, and 30 dBm with 35% (typical) PAE for PCS. Similarly, at low voltage of 2.8 V, minimum power out is given as 32 dBm for EGSM and GSM-850 bands, and 29 dBm for DCS and PCS bands. For receiver band noise, the performance is specified at -84 dBm/100 kHz for low bands, while for high bands it is -77 dBm/100 kHz.

Functional operation supply voltage is 2.8 V to 4.5 V, and logic operational supply voltage is 2.65 V to 2.9 V, respectively. Package size is 10 mm × 9 mm × 1.5 mm. Sampling now, the PA module is slated for production in the first quarter of 2005. It is available in quantities of 100,000, priced at $2.90.
Freescale Semiconductor
www.freescale.com

RSS    Save to Del.icio.us  Digg This