Adnan Yusuf wrote: > The sdr for the masses circuit shows that the antenna input is 0 - 54 > mhz and the oscillator is 0 - 120 mhz, why is the local oscillators > frequency more than double of the antenna receiving frequency.
The digital phase shifters require twice, or four times, the desired working frequency as phase shifters drive. Basically, those are digital ring counters with phase shifted outputs at a fraction (1/2, 1/4, ...) of the input frequency. > my other question is that what kind of local oscillator will give me > that kind of range. A Digital Direct Synthesizer chip does... 73, Jose, CO2JA __________________________________________ Participe en Universidad 2008. 11 al 15 de febrero del 2008. Palacio de las Convenciones, Ciudad de la Habana, Cuba http://www.universidad2008.cu
