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SAW resonators provides reliable, fundamental-mode, quartz frequency stabilization of fixed-frequency transmitters operating at many frequencies such as 315Mhz, 433.92Mhz, 868.35Mhz etc, and usually is designed specifically for remote-control and wireless security transmitters, SAW resonators are designed to be the frequency control element in transmitters and receiver local oscillators, they allows reduced receiver bandwidths, which results …

Before we discuss how to design RF remote control transmitters using SAW resonator, we have to know the basic principle, how it works. Basically a simple transmitter – oscillator network, contains frequency control part, amplifier and data input for phase shift, the amplifier contains RF transistor and a few surrounding components, and frequency control part …

As one of the most important component on typical PT4301 or PT4302 superheterodyne receiver module board, we must choose 10.7Mhz ceramic bandpass filter correctly, or else the receiver module will have worse performance or stop working. Bandpass filter is an electronic device or circuit that allows signals between two specific frequencies to pass, but that …

SAW resonator enabled RF remote control transmitters still has largest market share today, especially on 300 – 450 Mhz OOK transmitters, so research into the design of SAW resonator enabled remote control transmitter is still very important. For every remote control transmitter application, we always recommend surface mount components and carefully designed RF PCB layout …

When we make RF remote control transmitters, customers may not know detail parameters inside such as frequency, output power and other jargons, but they may feel that some remote controls batch has longer remote control distance, while other remote control batch has shorter distance, so what’s the difference inside? Or we can ask, which component …

As PT4302 requires few external components to work, so PCB board layout is easier than before, but as always when design RF circuit, certain rules have to be followed. For quick and easy start, we can always refer to official layout recommended in PT4302’s datasheet, but if you’re interested in more details, we have write …

As written in previous post, the main components on typical PT4302 receiver module includes one PT4302 receiver chip, one crystal oscillator and one 10.7Mhz band filter, we can say all PT4302 is same standard, but we should carefully choose the other two components, as they will affect actual performance / operating distance greatly. First we …

RF receiver modules for common appliance has been evolved during these years, first, super-regenerative receiver modules have been gradually replaced by superheterodyne receiver modules, which provide far superior performance and stability, second, superheterodyne module itself is also constantly evolving, as we can recall, just a few years ago, there is a common near-field-jamming feature of …

As we mentioned in previous posts, before we submit product to compliance house for full testing, we should first contact compliance test house for a pre-compliance testing, to find out and make corrections if there are obvious power level or harmonics that doesn’t meet regulatory requirements, but before that, we also have to do a …