Patent ID: 6441682
Filing Date: 2002-08-27
Classification: H03H

Abstract:
An active polyphase filter with transconductor cross-coupling of filter sections, comprising:a. first to fourth inputs for applying a 4-phase input signal comprising first to fourth signal vectors, respectively, which succeed one another inphase by 90 degrees; b. first to fourth outputs; c. a first filter section comprising: i) X-reactances wherein: (1) each of the X-reactances are active balanced integrating circuits having one reactance input pair and one reactance output pair; and (2) each of the X-reactances are coupled to the first input, the third input, the first output, and the third output; and ii) M-terminals selectively coupled to reactance input pairs of the first filter section and reactance output pairs of the first filter section; d. a second filter section comprising: i) Y-reactances wherein: (1) each of the Y-reactances are active balanced integrating circuits having one reactance input pair and one reactance output pair; and (2) each of the Y-reactances are coupled to the second input, the fourth input, the second output, and the fourth output; and ii) N-terminals selectively coupled to reactance input pairs of the second filter section and reactance output pairs of the second filter section; and e. Z-transconductor pairs cross-coupling the reactances of the first filter section through the M-terminals and the reactances of the second filter section through the N-terminals.