| 摘要 |
<p>The filter includes first (1) and second (2) oscillating circuits tuned by voltage-controlled variable-capacitance diodes (6). It comprises variable-capacitance diodes (3) coupled between the first and the second oscillating circuits. The variable-capacitance diodes (6) for tuning the oscillating circuits and the variable-capacitance diodes (3) for coupling the first and second oscillating circuits (1, 2) are controlled by a common control voltage (V) in order to carry out the tuning of the filter to its working frequency and the critical coupling of the two oscillating circuits (1, 2). Application: portable radio transmitters/receivers. <IMAGE></p> |
