آر اف (فرکانس رادیویی) و بی‌سیم گیرندهٔ آر‌اف

Product Attributes

Introduction

The CMX991 is a single-chip, high performance, RF transceiver that provides the core functions required to implement a full-featured radio transmitter and receiver. It operates from 100MHz to 1GHz and its I/Q architecture supports multiple modulation types and bandwidths with a single radio design. The half-duplex CMX991 integrates Tx modulators, Rx demodulators, IF PLL and IF VCO subsystems to minimise the external circuits needed when implementing a complete transceiver. User-selected modes suit different application requirements.

The Tx path includes an I/Q modulator to accurately generate modulation at the IF frequency, which may then be translated to the final RF frequency by an integrated image-reject up-converter system. The I/Q modulator IF output is also made available for conversion to RF via external circuits, if desired.

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 CMX991 provides differential and single-ended Rx output options and differential amplifiers for flexible signal conditioning.

The CMX992 is a single-chip, high performance, RF receiver that includes the core RF and IF receive functions of the CMX991 above 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.

Both devices operate from a single 3.3V supply over a temperature range of -40℃ to +85℃ and are available in 48-pin VQFN (Q3) packages.

Features

• Rx (CMX991 and CMX992)
  • RF mixer with output select
  • 1st IF input select
  • Selectable low IF outputs (450kHz/455kHz)
  • 1st IF Variable Gain Amplifier (VGA)
  • 1st IF Signal Level Indicator (SLI)
  • Two-mode demodulator
  • I/Q Zero-IF with differential outputs
• Tx (CMX991 only)
  • I/Q modulator to IF
  • Image-reject up-converter
  • IF and RF outputs
• IF (CMX991 and CMX992)
  • IF LO synthesiser
  • IF VCO negative resistance amplifier
• 3.3V low power operation

Applications

• Analogue/digital multimode radio
• Software Defined Radio (SDR)
• Portable, mobile and base station terminals
• Data telemetry modems
• TETRA (CMX992)
• Automatic Identification System (AIS) transponders
• Constant envelope and linear modulation
• Compatible with CMX998 (CMX992 only)
• Narrowband: e.g. 25kHz, 12.5kHz, 6.25kHz
• Wideband: up to 2MHz
• APCO Project 25 (P25) Phase 1 and Phase 2
• TDMA: TIA-102.CAAB
• Satellite communications