Patent ID: 8838058

Claim:
A communications radio or transceiver having an extended upper operating frequency limit, comprising: a first intermediate frequency (IF) conversion stage constructed and arranged for receiving and converting a radio frequency (RF) input signal to a first IF signal; a second IF conversion stage constructed and arranged for converting the first IF signal to a second IF signal; wherein each of the first and the second conversion stages includes: an adjustable first attenuator for receiving an input radio frequency (RF) signal, an amplifier coupled to an output of the first attenuator, an adjustable second attenuator coupled to an output of the amplifier, a serial peripheral interface (SPI) arranged for adjusting the first and the second attenuators in response to SPI command words, a mixer coupled to an output of the second attenuator, and a buffer for applying a local oscillator (LO) signal that is supplied to the buffer, to an input of the mixer; a radio frequency (RF) synthesizer constructed and arranged for supplying the LO signal to the buffer in each of the conversion stages, wherein the LO signal supplied to each buffer is nominally −15 dBm; and wherein (i) each of the conversion stages is in the form of an integrated circuit chip, (ii) components of each of the conversion stages and electrical connections between the components of each conversion stage are dimensioned so that each chip has an upper operating frequency limit of at least 6 GHz, and (iii) the chips are separated from one another for achieving a desired isolation but are of sufficiently small size to enable the radio to be packaged in a relatively small space.