Patent ID: 8487693

Claim:
An oscillator comprising: N greater than unity gain amplifiers, N being at least two, each of said N greater than unity gain amplifiers having a pair of differential input terminals and a pair of differential output terminals; a first pair of variable resistances coupling: a negative one of said pair of differential output terminals of a last one of said N greater than unity gain amplifiers to a positive one of said pair of differential input terminals of a first one of said N greater than unity gain amplifiers, and a positive one of said pair of differential output terminals of said last one of said N greater than unity gain amplifiers to a negative one of said pair of differential input terminals of said first one of said N greater than unity gain amplifiers; N−1 pairs of variable resistances coupling said pairs of differential output terminals of each of said N greater than unity gain amplifiers, other than said last one of said N greater than unity gain amplifiers, to said pairs of differential input terminals of its downstream neighbor; N−1 pairs of variable capacitances coupling said pairs of differential input terminals of each of said N greater than unity gain amplifiers, other than said last one of said N greater than unity gain amplifiers, to said pairs of differential output terminals of its downstream neighbor; and a variable capacitance coupling said pair of differential input terminals of said last one of said N greater than unity gain amplifiers to each other; wherein said N greater than unity gain amplifiers each in turn comprise: a linearized operational transconductance amplifier stage coupled to a corresponding pair of said differential input terminals; and a unity gain buffer with feedback interconnected between said linearized operational transconductance amplifier stage and a corresponding pair of said differential output terminals.