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Transmitter Reference Design for a 900MHz Full-Duplex Radio

Abstract: This reference design covers the design of a transmitter inside a 900MHz full-duplex radio using the MAX2902 single-chip transmitter. The MAX2902 is designed for use in the 869MHz to 915MHz frequency band, and complies with FCC CFR47 part 15.247 902MHz to 928MHz ISM band specifications. The reference design is capable of delivering more than +19dBm with V_CC = 2.9V and I_CC = 170mA, and +20dBm with V_CC = 3.3V and I_CC = 190mA, while meeting 14dB of CNR (1.22Mbps BPSK) at 10:1 VSWR (all angles). More detailed image (PDF, 213kB)System Performance Summary

Parameter	Conditions and Comments			Target	Measured	Units
Supply Current	Shutdown mode (LDOEN = LOW), VCC = 4.5V (worst case)				1.7	µA
	For +17.5dBm at LPF output (VASK = 2.1)(Power at balun output is approx 1dB higher, due to BPF, T-line, SMA)EVM for specified VSWR (worst-case phase angle) is less than 20%			VASK = 2.1VSupply current for the reference design is less than 10mA higher than the EV kit at full power. This is due to the increased bias to the PA that decreases the VCO pulling.Reference design allows a higher nominal output power for same EVM. More detailed image (PDF, 218kB)The MAX2902 is single-chip transmitter designed for use in 868MHz to 915MHz frequency bands. It complies with FC CFR47 part 15.247 902MHz to 928MHz ISM band specifications.The transmitter IC offers a high level of integration while minimizing external components. The transmit modulator, power amplifier, RF VCO, 8-channel frequency synthesizer, and baseband PN sequence lowpass filter are all integrated. By filtering BPSK modulation, the spurious emissions are reduced, enabling up to 8 independent transmit channels in the U.S. ISM band. Inputs are provided for spread-spectrum BPSK, ASK, and OOK. FM can be achieved by directly modulating the VCO. The device is intended primarily for use with external differential antenna.In this reference design the MAX2902 is applied as the transmit IC in the 900MHz band. It is controlled by a National Semiconductor LMX2353 fractional-N PLL. Kyocera is a registered trademark of Kyocera Corporation. Murata is a registered trademark of Murata Manufacturing Co., Ltd. National Semiconductor is a registered trademark of National Semiconductor Corp. SPI is a trademark of Motorola, Inc. 关键词： 电子电路图，Design 阅读全文 加入微信 获取电子行业最新资讯 搜索微信公众号：EEPW 或用微信扫描左侧二维码 相关电路 电源和电话滤波器电路 2012-07-27 电子电路图，电源滤波器 电话滤波器 浪涌电流限制电路图 2012-07-27 电子电路图，浪涌电流 整流滤波 用电流传感器进行电流检测电路图 2012-07-27 电子电路图，电流传感器 电流检测 检测电路图 毫米波E面金属膜片窄带滤波器的研究 2012-07-27 电子电路图，毫米波 金属膜片 窄带滤波器 EMI滤波器电路 2012-07-27 电子电路图，EMI滤波器 滤波器电路 LM318构成的低通可调滤波电路 2012-07-27 电子电路图，LM318 滤波电路 利用陷波滤波器的自动调谐电路设计 2012-07-27 电子电路图，陷波滤波器 自动调谐电路 有源滤波器中的相位关系考察 2012-07-27 电子电路图，有源滤波器 相位