AN611 Datasheet, PDF (1/3 Pages) Maxim Integrated Products – TD-SCDMA Radio Chipset Block Diagram for Handset Application

WIRELESS, RF, AND CABLE
Jun 01, 2001
TD-SCDMA Radio Chipset Block Diagram for
Handset Application
China option for 3G cellular phone is the TD-SCDMA system. A detailed
handset transceiver diagram is presented showing MAX2361 as the
transmit IC, the MAX2291 as the power amplifier (PA), and the MAX2388
and MAX2309 form the receiver. A VCO buffer amplifier is used to provide
isolation and maintains a clean LO signal.
Overview
TD-SCDMA is the third-generation (3G) cellular phone standard currently under development in
China. In November 1999, the TD-SCDMA standard was adopted by the ITU as one of the
options in the 3GPP mobile communication standard.
TD-SCDMA combines time-division duplex (TDD) and CDMA with up-link (reverse-link)
synchronization, a software radio, and a smart antenna, to increase channel capacity and
improve bandwidth efficiency.
In the radio section of the handset, the TD-SCDMA radio section requires fast switching time,
high dynamic range, and high linearity in both the transmitter and receiver sections. Maxim's
chipset delivers the highest performance, the smallest implementation size, and the least
expensive radio solution available in the TD-SCDMA handset market. The following block
diagram shows a typical application.
Transmitter
The MAX236X is a complete quadrature transmitter, including a quadrature modulator, variable-
gain IF and RF amplifiers, an image-rejecting upconverting mixer, a dual RF and IF synthesizer,
and a dual-band power amplifier (PA) driver amplifier. It is the ideal transmitter for TD-SCDMA
because of these features:
q Output power of +8dBm with excellent ACPR
q A 100dB power-control range
q Dual integer-N synthesizers for IF and RF
q An image-reject upconverting mixer, which saves one SAW filter