A front-end amplifier circuit for receiving a biological signal includes a signal channel. The signal channel amplifies the biological signal to generate a detection current and includes a capacitive-coupled transconductance amplifier. The capacitive-coupled transconductance amplifier amplifies the biological signal with a transconductance gain to generate a first current.

A low order filter circuit having a frequency correction function, a frequency correction method for a low order filter circuit, and a high order filter circuit are provided. An analog to digital converter (ADC) may detect a peak of a signal processed by a second order filter unit, and after comparison and determination are performed by a digital correction unit, a frequency control signal is outputted as a feedback to a notch filter or a band-pass filter in the second order filter unit where frequency adjustment is performed. The high order filter circuit is integrated by a plurality of the low order filter circuits. Before correcting the high order filter circuit, switch units may restore the high order filter circuit to the low order filter circuits for correction, and then combine the corrected low order filter circuits to form the original high order filter circuit.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) a real capacitor, whose value exactly emulates the value of the quantum constant h termed a Planck capacitor; 2) a quantum admittance element, which has no classical equivalent, but which can be emulated by approximately 18 transistors of a coupled transconductor system; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple quantum admittances to each other under the control of an input. These four parts can be composed together to create arbitrary discrete-state, traveling-wave, spectral, or other quantum systems.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) a real capacitor, whose value exactly emulates the value of the quantum constant h termed a Planck capacitor; 2) a quantum admittance element, which has no classical equivalent, but which can be emulated by approximately 18 transistors of a coupled transconductor system; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple quantum admittances to each other under the control of an input. We describe how these parts may be composed together to emulate arbitrary two-state and discrete-state quantum or quantum-inspired systems including stochastics, state preparation, probability computations, state amplification, state attenuation, control, dynamics, and loss compensation.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) capacitors that represent termed Planck capacitors; 2) a quantum admittance element, which can be emulated efficiently via coupled transconductors; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple emulated quantum admittances to each other under the control of an input. We describe a Quantum Cochlea, a biologically-inspired quantum traveling-wave system with coupled emulated quantum two-state systems for efficient spectrum analysis that uses all of these parts. We show how emulated quantum transdmittance mixers can help represent an exponential number of quantum superposition states in the spectral domain with linear classical resources, even if they are not all simultaneously accessible as in actual quantum systems.

A method includes forming a resonator comprising a plurality of switched impedances spatially distributed within the resonator, selecting a resonant frequency for the resonator, and distributing two or more transconductance elements within the resonator based on the selected resonant frequency. Distributing the two or more transconductance elements may include non-uniformly distributing the two or more transconductance elements within the resonator.

A method includes forming a resonator comprising a plurality of switched impedances spatially distributed within the resonator, selecting a resonant frequency for the resonator, and distributing two or more transconductance elements within the resonator based on the selected resonant frequency. Distributing the two or more transconductance elements may include non-uniformly distributing the two or more transconductance elements within the resonator.

A method for matching a pair of composite circuit elements (CEs) included in a circuit includes fabricating N CEs (e.g., resistors, transistors, current sources, capacitors) designed to match and switches configurable, according to M different combinations, to connect N/2 of the N CEs to form a first composite CE and to connect a remaining N/2 of the N CEs to form a second composite CE. Sequentially in time, for each combination of the M combinations, the switches are configured to form the first and second composite CEs according to the combination and a characteristic of the circuit is measured that includes the formed first and second composite CEs. The characteristic indicates how well the formed composite CEs match. A final combination of the M combinations is chosen whose measured characteristic indicates a best match and the final combination is used to configure the switches to form the composite CEs.

A low order filter circuit having a frequency correction function, a frequency correction method for a low order filter circuit, and a high order filter circuit are provided. An analog to digital converter (ADC) may detect a peak of a signal processed by a second order filter unit, and after comparison and determination are performed by a digital correction unit, a frequency control signal is outputted as a feedback to a notch filter or a band-pass filter in the second order filter unit where frequency adjustment is performed. The high order filter circuit is integrated by a plurality of the low order filter circuits. Before correcting the high order filter circuit, switch units may restore the high order filter circuit to the low order filter circuits for correction, and then combine the corrected low order filter circuits to form the original high order filter circuit.

A phase-reconfigurable circuit with programmable power splitting for a dual-input power amplifier is provided. The circuit includes an I/Q generator to generate I and Q RF signals from an input RF signal. A first vector-sum phase-shifter processes the I and Q RF signals to produce a first RF output signal. Similarly, a second vector-sum phase-shifter processes the I and Q RF signals to produce a second RF output signal.