摘要 |
A tuning arrangement for a resonant circuit, the tuning arrangement having an output reactance dependent upon a plurality of input applied signals one of which is an input tuning signal, and comprising: an array of tuning circuits connected in a network whose output reactance is used to control the resonance frequency of the resonant circuit, each tuning circuit having a control input and having a reactance which varies in dependence upon the value of a control signal applied to the control input; means for generating a plurality of different control signals for application to the control inputs of the tuning circuits; and each such control signal varying substantially linearly with the input tuning signal throughout a predetermined range specific to that control signal, so that the frequency response of the resonant circuit to the input tuning signal is substantially linear throughout a desired range of the input tuning signal. The tuning circuits are preferably variable reactance elements such as MOS varactors and further control signals can be applied to control higher order components. |