Inductor-Less RF Mixer Circuit for Low-Noise Linear Conversion

The patent removes the active transconductance stage from the input stage entirely, extracting the problematic component that caused non-linearity. The input stage is redesigned to use only passive resistors and switching elements, eliminating the source of distortion and noise while maintaining signal conversion capability through the switching action itself.

The patent replaces the active electronic transconductance mechanism with a passive resistive switching mechanism. Instead of using active devices (transistors) to perform the voltage-to-current conversion, the invention uses resistors combined with switching elements that operate in a controlled resistive state, substituting an active system with a passive one to achieve better linearity.

The patent employs standard CMOS switching elements and resistors that are inexpensive to manufacture, replacing the need for expensive bipolar transistors. The design accepts the use of CMOS devices with higher inherent flicker noise but compensates through circuit topology that minimizes the impact, using cheap, easily manufactured components to achieve cost-effective noise performance.

The patent converts the potential harm of CMOS flicker noise into a benefit by designing a circuit where the switching elements operate in a manner that suppresses the noise contribution. The switching action and resistive configuration transform what would be a noise source into a controlled mechanism that actually reduces overall noise impact, turning the limitation of CMOS devices into an advantage.

The patent replaces inductive components with a resistive-capacitive switching network. Instead of using physical inductors for impedance matching and frequency selectivity, the invention uses resistors and capacitors combined with switching elements that create equivalent impedance characteristics and filtering action, eliminating the need for bulky inductor components.

The patent uses periodic switching action to achieve frequency-selective behavior that traditionally required inductors. The switching elements operate at specific frequencies to create effective impedance matching and filtering, using time-domain periodic operation to replace frequency-domain inductive behavior, thereby reducing device size while maintaining performance.

The patent extracts and removes inductor components from the mixer circuit, eliminating the element that creates integration complexity and scalability issues. The design achieves the necessary circuit performance through alternative passive resistive and capacitive mechanisms that are fully compatible with standard integrated circuit fabrication processes, enabling better integration and scaling.

The patent changes the fundamental parameters of the circuit design by transitioning from inductive to resistive-capacitive operation. This parameter change allows the circuit to achieve equivalent or superior performance using components that are easier to integrate and scale, modifying the operating principles to match the constraints and capabilities of integrated circuit technology.