Nonintegrating receiver
AssigneeAT&T Bell Laboratories
InventorGareth F. Williams
Life of this patent
Estimating the term…
Abstract
A nonintegrating, high sensitivity, wide dynamic range receiver is described. A voltage dependent current source is connected in negative feedback with a forward voltage amplifier. The transconductance of the current source is essentially independent of frequency within the signal bandwidth frequency, and the feedback pole is the dominant pole in the loop gain. To prevent saturation by high intensity input signals the receiver is combined with a range extender circuit.
Claims58
A nonintegrating receiver (FIG. 9), having an input capacitance C.sub.T, for amplifying a signal current i.sub.s having a bandwidth .DELTA.f comprising:
- an input terminal to which said signal current is applied and an output terminal at which an amplified output voltage v.sub.o appears,
- a voltage amplifier connected between said terminals, said amplifier having a forward voltage gain (A) with n (n=1,2 . . . ) poles therein at frequencies f.sub.ai (i=1,2, . . . n) outside said bandwidth, and
- a negative feedback circuit, connected between said terminals, including a current source for generating a feedback current i.sub.f which is proportional to v.sub.o and which is subtracted from i.sub.s at said input terminal, the transconductance g.sub.f of said current source being essentially independent of frequency within said bandwidth and being of opposite sign to the forward gain A,
- said feedback circuit in combination with the input capacitance C.sub.T of said receiver producing a feedback voltage gain .beta. with a feedback pole therein at a frequency f.sub.f, and
- said amplifier and said feedback circuit forming a loop circuit having a loop gain A.beta., and for stability said feedback pole f.sub.f being the dominant pole in .vertline.A.beta..vertline. versus frequency.
A nonintegrating receiver (FIG. 9), having an input capacitance C.sub.T, for amplifying a signal current i.sub.s having a bandwidth .DELTA.f, comprising:
- an input terminal to which i.sub.s is applied and an output terminal at which an amplified output voltage v.sub.o appears,
- a voltage amplifier having a voltage gain (-A) and being connected between said terminals, and
- a negative feedback circuit, connected between said terminals, including a current source for generating a feedback current i.sub.f which is proportional to v.sub.o and which is subtracted from i.sub.s at said input terminal,
- said current source having a transconductance g.sub.f which is essentially independent of frequency within .DELTA.f, and the gain A being large enough so that within .DELTA.f the equivalent input resistance R.sub.e =1/Ag.sub.f of said amplifier is smaller than the impedance of the receiver input capacitance C.sub.T, so that the response of said receiver is nonintegrating.
Dependencies are inferred from the claim text.