Abstract: A two-dimensional SQIF array and methods for manufacture can include at least two bi-SQUIDs that share an inductance. The bi-SQUIDs can be combined to establish a diamond-shaped cell. A plurality of the diamond shaped cells can be packed tightly together so that each cell shares at least three cell junctions with adjacent cells to establish the SQIF array. Because of the close proximity of the cells, the effect that the mutual inductances each cell has on adjacent cells can be accounted for, as well as the SQIF array boundary conditions along the array edges. To do this, a matrix of differential equations can be solved to provide for the recommended inductance of each bi-SQUID in the SQIF array. Each bi-SQUID can be manufactured with the recommended inductance to result in a SQIF having an increased strength of anti-peak response, but without sacrificing the linearity of the response.

Abstract: An amplifier and method for improving linear response includes a plurality of N bi-SQUIDs. Each bi-SQUID has a non-uniform bi-SQUID parameter ?i, described by ?i=2?LiIci?0 can be defined for each bi-SQUIDs from i=1 to N, where Li is the loop inductance, ic is the critical current, and ?0 is a flux quantum for each bi-SQUID. The non-uniform bi-SQUIDs can be connected in series or in parallel to establish a Superconducting Quantum Interference Filter (SQIF) array of bi-SQUIDs. Once connected, a mutual inductance between the connected bi-SQUIDs can be established. If the mutual inductance between connected bi-SQUIDs is accounted for, careful manipulation of the critical current or the loop size, or both, of each bi-SQUID can result in extremely uniform behavior (linear response) of the SQIF when considered as a whole, even though the behavior of the element bi-SQUIDs is non-uniform (different ?i, parameters).

Abstract: A cascaded oscillator array includes a first oscillator array and a second oscillator array. The first oscillator array includes at least three oscillator elements coupled unidirectionally in a first ring such that the first oscillator array outputs a first oscillating signal. Each of the at least three oscillator elements is coupled to receive a signal from a sensing element. The second oscillator array includes at least three oscillator elements coupled unidirectionally in a second ring such that the second oscillator array outputs a second oscillating signal. A first number of the at least three oscillator elements of the first oscillator array is the same as a second number of the at least three oscillator elements of the second oscillator. Each oscillator element of the at least three oscillator elements of the second oscillator array is coupled to receive an output signal from a single oscillator element of the at least three oscillator elements of the first oscillator.

Abstract: A cascaded oscillator array includes a first oscillator array and a second oscillator array. The first oscillator array includes at least three oscillator elements coupled unidirectionally in a first ring such that the first oscillator array outputs a first oscillating signal. Each of the at least three oscillator elements is coupled to receive a signal from a sensing element. The second oscillator array includes at least three oscillator elements coupled unidirectionally in a second ring such that the second oscillator array outputs a second oscillating signal. A first number of the at least three oscillator elements of the first oscillator array is the same as a second number of the at least three oscillator elements of the second oscillator. Each oscillator element of the at least three oscillator elements of the second oscillator array is coupled to receive an output signal from a single oscillator element of the at least three oscillator elements of the first oscillator.

Abstract: An ambient electric field detector comprising: a collection mechanism disposed to generate a current signal in response to the ambient electric field; an input current mirror operatively coupled to the collection mechanism and disposed to amplify and duplicate the current signal to generate a duplicate signal; and an odd number (i) of at least three nonlinear, over-damped, bi-stable elements coupled uni-directionally in a ring such that the ring of elements oscillates, wherein at least one of the elements has a different initial state than the other elements and each element is disposed to receive the duplicate signal.

Abstract: A system includes at least a first array connected to a second array. The first array includes an odd number, greater than one, of unidirectionally-coupled non-linear first array elements. The second array includes an odd number, greater than one, of unidirectionally-coupled non-linear second array elements. The second array elements are unidirectionally-coupled in a direction opposite the coupling direction of the second array elements. The first array is configured to receive an input signal and down-convert the input signal. The second array is configured to receive the down-converted input signal, further down-convert the down-converted input signal, and output a down-converted output signal. The down-converted output signal is down-converted to a multiple of the frequency of the input signal proportional to the number of arrays of the system. The system may operate at frequencies greater than 1 GHz and may be contained in a microchip or on a printed circuit board.

Abstract: An electrical/magnetic current sensing system includes a first collection mechanism configured to convert an electric field into surface charge, a second collection mechanism comprising a magnetic reactive material, and a sensor coupled to the first and second collection mechanisms. The sensor comprises an odd number, greater than or equal to three, of unidirectionally-coupled non-linear over-damped bi-stable elements. Each element comprises a resistive load, an operational transconductance amplifier (OTA) with a bipolar junction transistor differential pair, a cross-coupled OTA, and a non-linear OTA. Each element may comprise fully differential inputs and outputs. The sensor may be contained in a microchip or on a printed circuit board. A resident time difference readout device may be connected to the sensor, and may be configured to perform a power spectral density calculation. The sensor may include a resistance to voltage circuit connected between the second collection mechanism and the elements.

Abstract: A device includes a plurality of channel-capture circuits. Each circuit may include an array of N non-linear oscillators, wherein N?3, circularly connected to each other in series such that unidirectional signal flow occurs between the oscillators. Each circuit may be configured to capture a respective channel signal from a wideband signal containing a plurality of channel signals and convert its captured channel signal to a lower frequency. Each oscillator may include an oscillator input configured to receive an output signal from another oscillator, an oscillator output configured to provide an output for an input of another oscillator, a frequency capture input configured to receive at least a portion of the wideband signal, at least two amplifiers, and a control capacitor coupled to the output of the amplifiers. An analog-to-digital converter may be coupled to the output of each channel-capture circuit.

Abstract: In various embodiments, an apparatus for down-converting a first signal having a first frequency to a lower frequency is disclosed. The apparatus can include one or more arrays of N over-damped, bi-stable circuits unidirectionally-coupled from element to element.

Abstract: Certain spatio-temporal symmetries induce one array of a two-array coupled network of oscillators to oscillate at N times the frequency of the other array, where N is the number of oscillators in each array.