Frequency-shaping network using controlled sources

Claim 2

An active frequency-shaping network having a transfer function which is substantially insensitive to gain comprising: a first circuit arranged to provide first-order frequencyshaping, including at least a first current controlled current source; a second circuit arranged tO provide first-order frequencyshaping, including at least a second current-controlled current source; means to apply an input voltage to said first circuit; means to apply the output of said first circuit to the input of said second circuit; and means to derive the output of said frequency-shaping network from the output of said second circuit.

Claim 3

Apparatus as set forth in claim 1 wherein said first and second circuits include a voltage-controlled voltage source connected after each current-controlled current source to provide isolation, thereby making the coefficients of said transfer function independently variable to a substantial degree.

Claim 4

Apparatus as set forth in claim 2 wherein at least one of said first and second circuits is arranged to perform an approximate integration function.

Claim 5

Apparatus as set forth in claim 3 wherein the gain of said current-controlled current sources is less than unity.

Claim 6

An active frequency-shaping network comprising: a first multiinput summing device; a second multiinput summing device; a first impedance means connected from the output of said first multiinput summing device to the input of said second multiinput summing device; means to apply an input voltage to one input of said first summing device; a first first-order frequency-shaping means connected to the output of said first summing device; a second first-order frequency-shaping means connected to the output of said first first-order frequency-shaping means; a second impedance means connected between the output of said first first-order frequency-shaping means and one input of said first multiinput summing device; a third impedance means connected between the output of said first first-order frequency-shaping means and one input of said second multiinput summing device; a fourth impedance means connected between the output of said second first-order frequency-shaping means and one input of said first multiinput summing means; a fifth impedance means connected between the output of said second first-order frequency-shaping means and one input of said second multiinput summing means; means to derive the output of said active frequency-shaping network at the output of said second multiinput summing device characterized in that said first and second first-order frequency-shaping means comprise controlled sources.

Claim 7

An active frequency-shaping network comprising: a first multiinput summing device; a second multiinput summing device; a first impedance means connected from the output of said first multiinput summing device to the input of said second multiinput summing device; means to apply an input voltage to one input of said first summing device; a first first-order frequency-shaping means connected to the output of said first summing device; a second first-order frequency-shaping means connected to the output of said first first-order frequency-shaping means; a second impedance means connected between the output of said first first-order frequency-shaping means and one input of said first multiinput summing device; a third impedance means connected between the output of said first first-order frequency-shaping means and one input of said second multiinput summing device; a fourth impedance means connected between the output of said second first-order frequency-shaping means and one input of said first multiinput summing means; a fifth impedance means connected between the output of said second first-order frequency-shaping means and one input of said second multiinput summing means; means to derive the output of said active frequency-shaping network at the output of said second multiinput summing device characterized in that said first and second first-order frequency-shaping means comprise controlled sources.

Claim 8

Apparatus as set forth in claim 5 wherein at least one of said first and second first-order frequency-shaping means comprises: a sixth impedance means connected to the input of a current-controlled current source and a seventh impedance means connected across the output of said current-controlled current source.

Claim 9

Apparatus as set forth in claim 6 wherein said sixth impedance means comprises a resistor and said seventh impedance means comprises a capacitor.

Claim 10

Apparatus as set forth in claim 6 wherein the gain of said current-controlled current sure is less than unity.

Claim 11

Apparatus as set forth in claim 6 wherein said current-controlled current source comprises at least one transistor connected in a common base mode of operation.

Claim 12

Apparatus as set forth in claim 6 wherein said first and second first-order frequency-shaping means are integrators.

Claim 13

Apparatus as set forth in claim 6 wherein the output of said current-controlled current source is applied to an isolating circuit comprising a voltage-controlled voltage source.

Claim 14

Apparatus as set forth in claim 11 wherein the gain of said voltage-controlled voltage source is less than unity.