飞思卡尔RFX275-30 2.75G RF子系统
RFX275-30 2.75G RF Subsystem EDGE Transceiver and Power Amplifier The RFX275-30 subsystem provides a highly integrated, comprehensive radio solution for 2G EDGE terminals. This solution offers antenna-to-bits functionality using less board space than the previous generation. It utilizes a CMOS 90 nm-based, single-chip transceiver.
The RFX275-30 improves on Freescale’s firstgeneration EDGE subsystem with embedded intelligence and simplified layer-one programming. As multiband and multimode phone electronics become more complex and form factors become smaller, simplified programming is key to getting a phone right the first time.
Traditional RF baseband programming must consider all the critical timing between the transceiver, power amplifiers, switches, low noise amplifiers, baseband processors and voltage regulators. The digital baseband must perform many calibrations to control a transceiver and the detailed timing of all transceiver functions. This interaction results in significant time investment to complete phone development successfully. With Freescale’s revolutionary approach, an engineer enters a single command stating the desired channel and power level. This command sets the parameters and times the events so that system compliance is virtually assured.
The MMM7010 transceiver and the MMM6028 front-end power amplifier combine to make up the RFX275-30 full radio subsystem. This solution is based on Freescale’s revolutionary polar architecture that delivers an optimal balance of low current, small size and, most importantly, a radio that’s easier to manufacture.
The MMM7010 is a highly integrated GSM/ GPRS/EDGE transceiver that provides antenna-to-digital bits functionality in a compact 5.2 mm x 6.8 mm package. The transceiver operates over the GSM850, EGSM900, DCS1800 and PCS1900 transmit and receive frequency bands. The MMM7010 transceiver includes a VLIF receive architecture with integrated low-noise amplifiers (LNAs) and a polar modulation transmit architecture with direct phase modulation of the voltage-control oscillator (VCO) by a fractional N synthesizer. Both the receive and transmit VCOs are fully integrated. The polar architecture allows for a filter-free transmit lineup. A timing controller generates appropriate timing events for the transmitter calibration and the transmit/receive bursts, thereby limiting the RF hardware dependency of the baseband layer 1 engine software to an absolute minimum.
The MMM6028 is a quad-band Class 45 GSM/GPRS/EDGE power amplifier front-end module (FEM) functioning over the GSM850, EGSM900, DCS1800 and PCS1900 transmit and receive frequency bands. To simplify radio front-end design, the power amplification, power coupling, power detection, low-pass filtering, output power control and antenna switching functions are integrated into the power amplifier FEM. Two modes of power control are supported with the MMM6028: bias control for GMSK modulation and input power control for 8PSK modulation.
Significantly shorter test and development times with improved final yields
Complete antenna-to-bits functionality—no separate analog baseband required
Highest level of integration provides extremely compact board area
Freescale’s revolutionary Polar architecture provides: Complete closed-loop control for manufacturability ease
Extremely low current consumption
Complies with industry-standard DigRF interface for ease of design
Embedded control provides less dependency on Layer 1 software and simplifies software programming
RFX275-30 2.75G RF子系统方框图.
Quad-band: GSM850, EGSM900, DCS1800 and PCS1900
EDGE Class 45 operation
GMSK Power Class 4 operation in GSM850 and EGSM900 bands
GMSK Power Class 1 operation in DCS1800 and PCS1900 bands
EDGE Power Class E2 operation
Lowest current consumption
Direct-conversion/filter-free revolutionary Polar transmitter
Closed-loop power control
Streamlined programming model for rapid software implementation
DigRF interface to digital baseband processor
High immunity to remodulation
如今，诸如Oculus Rift和HTC Vive等最先进的VR系统都需要一根稍显麻烦的线缆，来降低延迟和确保高保真图像以及电能传输到头显。但用过的用户都对此深恶痛绝，线缆直接影响了沉浸感。这个问题激发了不少于七个解决方案，这些方案都致力在高端主机PC和头显之间建立无线链路。