CML CMX992单片RF接收方案

CML Microcircuits公司的CMX992是单片高性能RF接收器,工作频率从100MHz到1GHz,它的I/Q架构支持多种调制方式和带宽. CMX992集成了首级混频器,RX解调器,IF PLL和IF VCO子系统,从而最大限度地降低了接收器外部电路元件.用户可选择不同模式以适应不同的要求,可广泛用于模拟,数字和多模式无线电,SDR,手提,移动和基站终端以及WiMAX和卫星通信等.本文介绍了CMX992的主要特性,方框图, 应用方框图以及CMX992评估板的主要特性,评估板方框图以及详细的电路图.

CMX992: RF Quadrature/IF Receiver
The CMX992 is a single-chip, high performance, RF receiver IC. It operates from 100MHz to 1GHz and its I/Q architecture supports multiple modulation types and bandwidths with a single radio design. The CMX992 integrates first mixer, Rx demodulators, IF PLL, and IF VCO subsystems that minimize the external circuits needed to implement a complete receiver. User-selected modes suit different application requirements.

The Rx path includes an integrated 1st Rx mixer having two outputs to support two external 1st IF filter choices, then an integrated 2:1 input mux followed by VGA and wideband signal level measurement functions to support AGC implementation. The 1st IF signal is then either I/Q demodulated to zero IF or mixed to a low IF output. The CMX992 provides differential and single-ended Rx output options and differential amplifiers for flexible signal conditioning.

The CMX992 includes the core RF and IF functions of a high performance receiver and can be used in a wide range of narrowband and wideband wireless products including multi-mode analogue/digital terminals. The device operates from a single 3.3V supply over a temperature range of -40°C to +85°C and is available in a 48-pin VQFN (Q3) package.

The CMX992 can be used where highly linear modulations are being used, e.g. for applications such as TETRA, where a typical transmitter solution would include the CMX998 Cartesian Feedback Transmitter.

CMX992主要特性:
High Performance, Single Chip 100MHz to 1GHz RF Receiver
Rx
RF Mixer with A/B Output Select
1st IF Input A/B Select
1st IF Variable Gain Amplifier (VGA)
1st IF Signal Level Indicator (SLI)
Two-mode Demodulator
I/Q Zero IF with Diferential Outputs
Two Selectable IF Outputs (e.g. 450kHz, 455kHz)
IF
IF LO Synthesiser
IF VCO Negative-Resistance Amplifier
3.3 V Low Power Operation

应用:
Analogue, Digital and Multi-mode Radio
SDR (Software Defined Radio)
Portable, Mobile and Base Station Terminals
TETRA
APCO P25: Phase 1 and Phase 2 TDMA
Automatic Identification System (AIS) Transponders
Constant Envelope and Linear Modulation
Compatible with CMX998
Narrowband: 25kHz, 12.5kHz and 6.25kHz
Wideband: (eg.EN 302 561)
APCO Project 25: TIA-102.CAAB,
ETSI: EN 300 113, EN 301 166, EN 300 220,
TS 102 361 (DMR)
WiMAX
Satellite Communications



图1. CMX992方框图



图2. CMX992应用方框图

EV9920:CMX992 评估套件
The EV9920 allows the evaluation of the CMX992 Quadrature/Low IF Receiver.
The CMX992 includes only the receiver and IF LO sections of the CMX991 and is ideal for applications that do not require the CMX991 transmitter, for example when a linearised transmitter is required, in which case the CMX998 Cartesian loop transmitter IC could be used for Tx and the CMX992 for Rx.**
Access is provided to all CMX992 RF, baseband and control signals by either connector or test points. Test access points are available to accept common test equipments, such as RF and baseband signal generators and spectrum analysers.

All signal paths are matched by suitable components and the overall evaluation frequency range of this Evaluation Kit is for RF frequencies between 100MHz and 1GHz, with default operation over 450MHz to 470MHz. In the form of a populated PCB, this flexible Evaluation Kit enables users to configure and evaluate the CMX992 devices for various applications and frequency bands.
The on-board CMX992 IC is controlled via its C-BUS serial interface.
The PE0002 Interface Card is available separately to support PC-based control of the EV9920.

The PE0002 uses ES9910xx.exe PC software, part of the ES9910xx.zip file, which is available via the download hyperlink in the Support Package area below.

评估板主要特性:
CMX991 and CMX992 Evaluation
Receiver:
LNA
I/Q or IF Output
Selectable IF Filters
Test Access
450-470MHz default operation
100MHz to 1GHz evaluation
Transmitter (CMX991 Only)
PA Provided
IF and RF Outputs
I/Q Input Interface
Gain Control
PC control interface available
Interface to EV9810 or EV9100



图3.评估板外形图



图4.评估板方框图



图5.评估板电路图(1)



图6.评估板电路图(2)



图7.评估板电路图(3)



图8.评估板电路图(4)



图9.评估板电路图(5)



图10.评估板电路图(6)