| 摘要 |
A communications receiver such as an integrated zero IF receiver comprises an input for receiving an input signal and a zero IF frequency down conversion circuit coupled said input and constructed to provide quadrature related signals (I,Q) at a substantially zero intermediate frequency. In order to balance the signal paths, at least one capacitance in each of the quadrature related zero IF signal paths of the frequency down conversion circuit comprises at least two integrated capacitors connected in anti-parallel. By fabricating the integrated capacitances in this way the symmetry of the circuit is maintained which enhances significantly the second-order inter-modulation performance.
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