Patent ID: 7705658

Claim:
A wave detector circuit comprising: a first transistor having a base and a collector connected together, said first transistor receiving an AC signal having a wavelength and a reference voltage at said base and said collector; a first resistor; a second transistor having a base and a collector, said base of said second transistor being connected to said base of said first transistor through said first resistor, said second transistor outputting a detected voltage at said collector of said second transistor; and a diode-connected temperature compensation transistor connected between ground potential and said base and said collector of said first transistor, wherein said base of said second transistor is only connected to said first resistor, and no reactive element is connected to said base of said first transistor or to said base of said second transistor that produces a frequency dependent connection between said base of said first transistor and said base of said second transistor.