| 摘要 |
A digitally controlled wideband phase shifter is disclosed in which an input signal is resolved into two quadrature related components, the components are scaled in a stepped digital manner in proportion to the sine and cosine of the phase shifting angle, and then recombined to reconstitute a phase shifted replica of the input signal. The scalers are segmented MESFETS of a dual gate design in which each segment, has a predetermined transconductance and may be gated "ON" or "OFF" by a control signal to affect the overall transconductance of the scaler, and thereby the scaling factor. The phase shifter is implemented by a monolithic microwave integrated circuit technique in which the preferred substrate material is gallium arsenide, and in which all active device and circuit features are formed on the substrate by a photolithographic process. The phase shifter is adapted to scaling at stepped angles, typically 111/4 or 221/2 degrees, is broadband and is applicable to frequencies ranging from a fraction of a gigahertz to many gigahertz.
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