As the industry of wireless communication is explosively growing up, it has led to the spread of different communication standards and a higher consumer demand for low power, low cost RF ICs. At present the multistandard communication market tends to converge into IMT2000 for highly performance multimedia world. As a result, there is a demand for RF ICs that cad adapt to the various communication standards.
There are many materials and devices for implementation of the RF ICs with low cost and high performance but Si technology is the best candidate from the viewpoint of low cost.
This work focuses on the implementation of a monolithic RF Mixer that follows the analysis of RF transceiver architecture for GSM and IMT2000(WCDMA) dual band application. The designed down and up Mixers are based on the Gibert active topology and implemented using the 0.8μm 12GHz ＄f_t＄ BiCMOS process with the package of TSSOP 24pin for the receiver and TSSOP 28pin for the transmitter. The measurement results of GSM down mixer indicate the conversion gain of 4.6dB, the input PldB of-6.5dBm, the input IP3 of 2.5dBm and the SSB noise figure of 12dB drawing the total current of 12mA from a 2.7V power supply. WCDMA down mixer has the conversion gain of 2.2dB, the input P1dB of -7.5dB, the input IP3 of 1.5dBm, the SSB noise figure of 12.6dB and 22mA current consumption from a 2.7V power supply. WCDMA up mixer has the conversion gain of 15dB, the output P1dB of -8dBm and current consumption of 28mA from a 2.7V power supply.
본 논문에서는 앞으로 가장 수요가 많을 것으로 예상되는 통신 표준인 GSM과 IMT2000 중에서 유럽에서 상용화될 WCDMA를 모두 지원하는 송수신구조가 먼저 제안되고 각 규격에 맞는 구성요소의 사양을 결정한 후 RF Front-end 에서 큰 비중을 차지하는 down mixer 및 up mixer를 설계하고 구현한 후 측정을 통해 검증하였다.
Package model를 포함하여 Cadence Spectre RF를 통해 simulation 하였고, AMS의 0.8μm Si BiCMOS 공정을 이용하여 제작되었으며, TSSOP 형태로 Packaging 되어 4층 PCB 기판에서 측정되었다.
GSM down mixer의 경우 4.6dB의 Conversion Gain과 -6.5dBm의 Input P1dB, 2.5dBm의 ⅡP3, 12dB의 SSB NF를 얻었으며, WCDMA down mixer는 2.2dB의 Conversion Gain, -7.5dBm의 Input P1dB 1.5dBm의 ⅡP3와 12.6dB의 SSB NF의 특성을 가졌다. WCDMA up mixer는 15dB의 Conversion Gain, -8dBm의 Ourput P1dB 및 1.8dBm의 OIP3를 나타내었다.
제작된 Prototype Chip은 GSM 및 WCDMA 단말기에 응용될 수 있을 것이며, 나머지 구성 요소들을 함께 집적함으로써 One-Chip 송수신기를 구현할 수 있을 것으로 기대된다.
