MARCdevices Co., Ltd.
|MARCdevices Co., Ltd. Patent applications|
|Patent application number||Title||Published|
|20150381145||IMMITTANCE CONVERSION CIRCUIT AND FILTER - An immittance conversion circuit includes a first terminal and a second terminal, and includes: a conversion target circuit configured to amplify or attenuate a signal with desired frequency and gain characteristics, and output the resultant signal; a difference signal detection circuit configured to supply the input terminal of the conversion target circuit with a signal of a difference between signals generated at the first and second terminals; an immittance conversion drive circuit configured to perform differential output processing to generate a voltage of a difference between a correction voltage and the signal outputted from the conversion target circuit, and output feedback signals to an immittance conversion generation circuit; and the immittance conversion generation circuit having an immittance conversion generation action to generate, at each of the first and second terminals, a signal of currents or voltages of the corresponding inputted feedback signal and the signal inputted to the first or second terminal. A signal of a difference between the signals generated at the first and second terminals is inputted to the immittance conversion drive circuit as the correction voltage.||12-31-2015|
|20130027148||ANTIRESONANT FREQUENCY-VARYING COMPLEX RESONANT CIRCUIT - A complex resonant circuit includes: a first current path performing a first gain control to an AC power signal being supplied; at least one second current path performing a second gain control different from the first gain control to the AC power signal; at least two resonant circuits provided on the respective first and second current paths, having mutually different resonance or antiresonance points for the AC power signals passing through the respective first and second current paths and capturing the respective AC power signals; at least one compensation current path performing a compensation phase shift to the AC power signal; a compensation circuit, provided on the compensation current path, for removing an unnecessary component of the resonant circuit; and an analog operational circuit performing analog addition or subtraction on the AC power signal having passed through the first and second current paths, and the compensation current path.||01-31-2013|
|20130027143||ANTIRESONANT FREQUENCY-VARYING COMPLEX RESONANCE CIRCUIT - A complex resonance circuit includes a first current path performing a first phase shift and a first gain control to an AC power signal supplied, at least one second current path performing a second phase shift different in amount from the first phase shift and a second gain control different in amount from the first gain control to the AC power signal, at least two resonant circuits which are provided each on the respective first and second current paths, and have mutually different resonance points or antiresonance points for the AC power signals each passing through the respective first and second current paths and capture the respective AC power signals, and an analog operational circuit for allowing the AC power signals having passed through the first and second current paths to be subjected to addition or subtraction in an analog fashion for output.||01-31-2013|
|20120223782||COMPLEX NEGATIVE FEEDBACK FREQUENCY SELECTION OUTPUT CIRCUIT AND OSCILLATION CIRCUIT USING THE SAME - It is an object to provide a complex negative feedback frequency selection output circuit that can produce an output signal of a high resonance sharpness Q factor and an oscillation circuit using the same. The complex negative feedback frequency selection output circuit according to the present invention, frequency-selectively relays only the residual components of one of a signal in phase with (or a signal opposite in phase to) a feedback processed signal obtained by negative feeding back a feedback signal to an input frequency signal, with a rejected frequency band being left out, while relaying at least a real number component of the other, and comprises a feedback path which relays a difference signal between (or a sum signal of) the selectively relayed output and the relayed output of the real number component, as the feedback signal. The gain of a loop including this feedback path is variable and can be set manually or automatically.||09-06-2012|
|20110148515||QUASI-RESONANT COMPOSITE RESONANCE CIRCUIT - A composite resonance circuit is provided of which the resonance frequency is variable over a wide frequency range without changing the circuit constant of a non-resonant element having no resonance frequency. The composite resonance circuit comprises an input terminal; a resonance unit having first and second ports and quasi-resonating in response to AC signals respectively supplied to these ports; and phase shift circuits that perform different phase shifts on an AC signal supplied to the input terminal and supply first and second shifted signals subjected to the phase shift respectively to the first and second ports. The resonance unit is an impedance circuit that has at least four input terminals forming the first and second ports and that generates a quasi-resonant peak current under non-zero reactance in response to the first and second shifted signals coming in via the first and second ports. The quasi-resonant peak current is variable according to the frequency and phase shift quantities of the AC signals. Namely, the resonance frequency can be made to be variable.||06-23-2011|
|20110148514||FREQUENCY VARIABLE COMPOSITE RESONANCE CIRCUIT - A composite resonance circuit is provided of which the resonance frequency range can be set with greater degrees of freedom with the peak frequency of the resonance characteristic curve of a resonance unit having good linearity and the resonance sharpness Q-factor being kept within a desired range. In the composite resonance circuit according to the present invention, first and second relay circuits are respectively connected between the resonance unit and first and second phase shift circuits that shift an input frequency signal by different phases. Hence, the resonance frequency range can be set by setting the gains and impedances of the first and second relay circuits according to its use, without changing resonance elements or the like of the resonance unit.||06-23-2011|
Patent applications by MARCdevices Co., Ltd.