Software Defined Radio

Overall Schematic
USB Controller
AD9958/59 DDS



  The USB controlled software defined transceiver is currently in the
prototype stage. I have 2 sets of PC Boards on hand. Each of the
boards is 1.5" X 3.5" . Five boards make up the design.

USB Controller:
The USB controller is a Cypress Cy7C68013A (the FX2LP) USB 2.0
interface with build in 8051 compatable microprocessor. One prototype
has been built and tested.

AD9958/59 DDS:
The prototype uses an AD9959 quad DDS plus 200 MHz Low Pass Filters
for each channel and a high speed copmarator on each channel. The
2-channel AD9958 could be substituded (same pin-out) and only populate
the filters and comparators for the 2 channels. The AD9958/59 provide
2/4 independent channels. Each channel can have independently
programmed frequency, phase and amplitude. Starting of each channel
can be synced to a common pulse ensuring control of relative phases.
With the AM modulation capability, it should be possible to produce
SSB (or any other modulation type) at up to 200MHz. One board has
been assembled and tested with the Analog Devices control program.
The AD9959 on this board was able to be clocked at 750MHz OK. The board
uses a 125MHz canned oscillator. Multiplies of 4, 5 , and 6 all worked

QSD: The Quad Sampling Detector is very similar to the Softrock 40
design(except for the LO). The AD9958/59 will drive the LO directly.

BPFs: The band pass filter board has 6 band pass filters for the HF
spectrum. Two FST3251's are used to switch the filters. Ptototype boards
have been produced but not assembled or checked out yet.

QSE-ADC-DAC: This board has the quad sampling exciter, an Analog to
Digital Convertor, and a Digital to Analog convertor. Both the ADC
and the DAC are stereo 24bit at 192KHz. The QSE is the same design in
the 4 part QEX article on SDR for the Masses. Prototype boards have been
produced but not populated yet.