Abstract: A planar inductor structure with improved Q compatible with typical integrated circuit fabrication. The structure includes a spiral inductor with a conductive plane between the resistive substrate of the integrated circuit and the spiral inductor which reduces the power loss of the inductor. A pattern of segments may be formed in the conductive material of conductive plane to prevent eddy currents from flowing through the conductive plane and reducing the inductance of the spiral inductor. The Q of the inductor can be enhanced by optimizing the pattern in which the segmented conductive plane is formed. The segmented conductive plane may be fabricated out of metal, polysilicon or a heavily-doped region of the substrate.

Abstract: A time-share mixer circuit and a frequency converter, an I-Q modulator, and an I-Q demodulator. A switching signal drives the time-share mixer circuit to alternate between two output signals. The first output signal represents the output of a mixer having a given signal input and a local oscillator signal with a first phase as its local oscillator input. The second output signal represents the output of the mixer having the same input signal and the local oscillator signal with a second phase that differs from the first phase by 90 degrees as its local oscillator input signal. The frequency converter uses the time-share mixer in combination with a switched output phase shifter that switches in sync with the phase of the local oscillator signal to generate a phase shifted output signal in which the time average of an undesired image signal is substantially reduced compared to time average of the desired signal. The phase shifted output signal is then amplified by a bandpass amplifier.