RF Building Blocks
CMX992 – RF Quadrature/Low IF Receiver
The CMX992 is a single-chip, high performance, RF receiver IC for analogue and digital radio systems. It operates from 100MHz to 1GHz and this RF quadrature receiver / Low IF receiver 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 minimise 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 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.
Devices are available through our Distributor Network.
Features
- High Performance (100MHz to 1GHz) RF Receiver
- Rx:
– RF Mixer with Output Select
– 1st IF Input 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 (450kHz or 455kHz) - IF:
– IF LO Synthesiser
– IF VCO Negative-Resistance Amplifier
Applications
- Analogue, Digital and Multi-mode Radio
- Software Defined Radio (SDR)
- Portable, Mobile and Base Station Terminals
- TETRA and APCO P25: Phase 1 and Phase 2 TDMA
- Automatic Identification System (AIS) Transponders
- Constant Envelope and Linear Modulation
- Compatible with CMX998
- Narrowband Systems: 25kHz, 12.5kHz and 6.25kHz
- Wideband Systems:(eg.EN 302 561)
- APCO Project 25:TIA-102.CAAB, ETSI: EN 300 113, EN 301 166,
EN 300 220, TS 102 361 (DMR) - Satellite Communications
Power Supply Requirement
- 3.3 V
Design Resources
CMX992 and EV9920B Questions
Q. What spurious response rejection can I expect from the EV9910B/EV9920B receiver?
A. The EV9910B/EV9920B has been tested for receiver spurious responses to EN300-113 with a 9600 baud GMSK modem.
The performance was limited only by the image rejection (approximately 30dB), other rejections being greater than the required 70dB.
The user may provide additional image filtering between the LNA and mixer input; this is detailed in the user manual.
CMX991 and CMX992 Operation Below 100MHz
This Application Note seeks to provide useful guidance on the use of the devices below 100MHz and contains details of how such operation can be demonstrated through component changes to the matching circuits on the EV9910B and EV9920B Evaluation Kits.
Frequency Estimation for a VCO using a Negative Resistance Amplifier
Application Note describing how to estimate the operating frequency of VCO designs using a negative resistance amplifier. An Excel spreadsheet that automates the calculation is available below.
Excel Spreadsheet - Frequency Estimation for a VCO using a Negative Resistance Amplifier
An Excel spreadsheet that calculates the operating frequency of VCO designs using a negative resistance amplifier. An Application Note describing the process is available above.
EV9910B/EV9920B - PDT* Configuration
Using the EV9910B and EV9920B to evaluate the CMX991 and CMX992 RF ICs for the Chinese *Police Digital Trunking (PDT) system.
CMX7164 2FSK 4FSK RAW Scripts
The two scripts contained in the ZIP file demonstrate the use of 2/4FSK transmitting and receiving up to 7 million bits of raw data through an RF wireless link. These scripts require the following evaluation boards: Two x PE0003, Two x PE0601-7164, One x EV9980, One x EV9920B. It is important to read the included readme.txt file. It is recommended that you read the QAM + RF Demonstration application information and watch the YouTube video for the Full QAM + RF Demo" as the setup of the evaluation boards is the same.
PE0601-7164 - 2FSK 4FSK Formatted Scripts
The two scripts contained in the ZIP file demonstrate the use of 2/4FSK transmitting and receiving Block 2 Formatted data through an RF wireless link. The Data frame consists of Header Block, Intermediate Block and Last Block. These scripts can be easily modified to support other Block Types. These scripts require the following evaluation boards: Two x PE0003, Two x PE0601-7164, One x EV9980, One x EV9920B. It is important to read the included readme.txt file. It is recommended that you read the QAM + RF Demonstration application information and watch the YouTube video for the Full QAM + RF Demo" as the setup of the evaluation boards is the same.
| EV9910B/EV9920B | The EV9920B allows the evaluation of the CMX992 Quadrature/Low IF Receiver. Access is provided to all CMX992 RF, baseband and control signals by either connector or test points. | EV9920B_Product_Preview
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