Ultra-compact RF transmitters boost range and simplify design

A trio of compact new RF transmitters has been introduced by Radiometrix, allowing designers to build longer-range low-power radio systems in space-constrained applications that cannot accommodate a conventional 12.5 kHz/ 25kHz narrowband FM transmitter. The MTX1, MTX2, and MTX3 are 4-channel transmitters operating on 120-180MHz, 420-470MHz and 850-950MHz respectively. State-of-the-art RF components keep module measurements to a compact 23mm x 12.5mm x 7mm, while +10dBm transmit power allows a typical usable range of up to 500 metres with a matching narrow band receiver. The transmitter's conformance to EN 300 220-2 (radio) and EN 301 489-3 (EMC) assures high performance and meets all regulatory requirements for license-exempt short-range devices. Built-in shielding enables slim-line equipment designs, while avoiding additional mechanical design complications, while careful and robust circuit design reduces susceptibility to mechanical vibrations, to ensure a clean and reliable signal under challenging operating conditions. Each module contains the transmitter IC and baseband circuitry, with user-accessible digital and analogue inputs, which enables even analogue signals like AFSK, GMSK, DTMF tones to be transmitted. A 3V voltage regulator and brown-out reset controller are also built in. Programming is via a simple RS-232 serial interface. The wide input voltage range of 3.1V to 15V also helps simplify system design while energy conscious performance (drawing typically 20mA) maximises the lifetime of battery-powered applications. With their small dimensions, low power operation and high reliability, combined with extended range, the MTX1, MTX2 and MTX3 deliver superior performance in a wide range of applications. These include vehicle key fobs and other handheld devices, small-form-factor data loggers, industrial telemetry and controls, smart-building devices, high-end security systems and fire alarm sensors, and heavy-vehicle controls.