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How not to design transmitters and receivers (part 11: reference oscillators)
16/09/21
In an earlier 'How not to design transmitters and receivers' it was blithely stated that the reference oscillator part of a phase locked loop (PLL) was a relatively trivial undertaking. And... it is. All that needs to be decided is what the reference frequency is going to be.
T -
How not to design transmitters and receivers (part 10: varicaps)
14/09/21
Before heading down the final straight of the Wireless Waffle lockdown transmitter project, and mounting the horse of the associated receiver, a few words on varicap diodes, or varactors as they're also known.
A varicap is a diode which, when reverse biassed (i.e. not conducting) a -
How not to design trasmitters and receivers (part 9: low-pass filters)
06/09/21
Many designs for transmitters and power amplifiers which can be found online (certainly some of the older designs such as the one below) fail to include any low pass filtering on their outputs.
There are several possible reasons for this:Let's first look at what service -
How not to design transmitters and receivers (part 8: divide by N)
03/09/21
The next functional block that is required to complete a transmitter (not a receiver for which there are many other blocks to consider) is the 'divide by N' device. In principle, all that is required to achieve this function is a counter which will count up (or down) until it reaches a pa -
How not to design transmitters and receivers (part 7: phase comparators)
01/09/21
One of the blocks yet to be discussed in the Wireless Waffle lockdown transmitter and receiver project is the phase/frequency comparator. In days of yore (a.k.a. the 1980s), the go-to integrated circuit (IC) for this function was the trusty 4046. This not only contains a couple of different types
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How not to design transmitters and receivers (part 11: reference oscillators)
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