S. Lucyszyn et al., 24 GHZ SERRODYNE FREQUENCY TRANSLATOR USING A 360-DEGREES ANALOG CPW MMIC PHASE-SHIFTER, IEEE microwave and guided wave letters, 4(3), 1994, pp. 71-73
A 360-degrees analog CPW MMIC phase shifter is presented for the first
time. The compact MMIC employs eight multilayer 3 dB quadrature coupl
ers and was fabricated using low cost GaAs foundry processing techniqu
es. The phase shifter was required to implement a narrow band serrodyn
e frequency translator at 24 GHz. With an arbitrary, small-shift, freq
uency translation of +5 KHz, the measured results demonstrated a carri
er suppression of 30 dB and an image sideband suppression of 13 dB. Th
is was achieved with a simple linear sawtooth signal, providing 22% of
under-modulation. In addition, a 0 dB conversion loss was achieved an
d almost no control power was required.