| 摘要 |
A phase shifting arrangement for generating a set of mutually orthogonal signals, comprising: a phase shifting unit for receiving an input signal and having a first phase shift circuit for generating a first output signal phas e- shifted by a first amount with respect to the input signal, a second phase shift circuit for generating a second output signal phase-shifted by a secon d amount with respect to the input signal, and a third phase shift circuit for generating a third output signal phase-shifted by a third amount with respec t to the input signal; the phase shift caused by each of the first, second and third phase shift circuits being adjustable in response to a feedback signal ; and a phase shift adjustment circuit for generating the feedback signal and arranged to receive the first, second and third output signals and a fourth output signal of the same phase as the input signal and thereby generate an error signal dependent on the deviation of the first, second, third and four th signals from mutual orthogonality; and a feedback circuit arranged to receiv e the error signal and form the feedback signal in dependence thereon in so as to cause the first, second and third phase shift circuits to, on receiving t he feedback signal, generate the first, second and third signals in closer orthogonality to each other and to the input signal.
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