Embodiments disclosed herein relate to improving an available bandwidth for a transceiver of an electronic device and to reducing a footprint of an associated integrated circuit of the electronic device. To do so, an isolation circuit is disposed between a transmit circuit and a receive circuit. The isolation circuit has first and second signal paths. A first portion of the signal propagates along the first signal path and a second portion of the signal propagates along the second signal path. A non-reciprocal phase shifter is disposed on the first signal path to shift a phase of the first portion to match a phase of the second portion and improve isolation between the transmit circuit and the receive circuit. The phase-shifted first portion may be combined with the second portion to reduce or substantially eliminate an insertion loss caused by the isolation circuit.

A switched-capacitor circuit comprising a differential operational amplifier and a feedback circuit is described. In some embodiments, the feedback circuit may be configured to provide a reference voltage that is insensitive to temperature and/or process variations. In some embodiments, the feedback circuit may be configured to mitigate the time delay associated with one or more capacitors of the switched-capacitor circuit. The switched-capacitor circuit may be controlled by a pair of control signals. During a first phase, one or more capacitors may be charged, or discharged, through an input signal. During a second phase, the electric charge of the one or more capacitors may be retained.

An AC coupler for transmitting high-frequency components of a wideband signal includes a signal conductor and a shielding structure arranged as a transmission line. The signal conductor includes a conductive element and a capacitor configured to block direct current (DC) components of the wideband signal while transmitting high-frequency alternating current (AC) components of the wideband signal. The shielding structure is configured for conducting at least the AC components of the wideband signal while confining electric fields and currents in the shielding structure substantially to a region proximate to the signal conductor. The shielding structure has a width substantially greater than a width of the signal conductor. The difference between the shielding structure width and the signal conductor width may be substantially greater than an offset distance between the signal conductor and the shielding structure.

An equivalent circuit includes a first capacitor having a first capacitance, a circuit part configured to include an inductor component, a capacitor component, and a resistor connected in series with one another, the circuit part being connected in parallel with the first capacitor, and a second capacitor provided between the first capacitor and the circuit part and having a second capacitance. The first capacitance of the first capacitor changes in accordance with a voltage value of a direct current voltage applied to the first capacitor. The second capacitor has the positive second capacitance that changes in accordance with the voltage value of the direct current voltage applied to the first capacitor and that is N times (N>0) the first capacitance of the first capacitor.

An equivalent circuit includes a first capacitor having a first capacitance, a circuit part configured to include an inductor component, a capacitor component, and a resistor connected in series with one another, the circuit part being connected in parallel with the first capacitor, and a second capacitor provided between the first capacitor and the circuit part and having a second capacitance. The first capacitance of the first capacitor changes in accordance with a voltage value of a direct current voltage applied to the first capacitor. The second capacitor has the positive second capacitance that changes in accordance with the voltage value of the direct current voltage applied to the first capacitor and that is N times (N>0) the first capacitance of the first capacitor.

The present invention relates to a frequency selective security paper and a method for manufacturing the same. The frequency selective security paper according to an exemplary embodiment of the present invention may include: a drafting paper for forming a paper; a frequency resonator formed on one surface of the drafting paper and formed in a form of a meandering line or a capacitor so as to resonate to a designated frequency when passing through a security search device; and a coating liquid including the frequency resonator therein and formed on the drafting paper.

The present invention relates to a frequency selective security paper and a method for manufacturing the same. The frequency selective security paper according to an exemplary embodiment of the present invention may include: a drafting paper for forming a paper; a frequency resonator formed on one surface of the drafting paper and formed in a form of a meandering line or a capacitor so as to resonate to a designated frequency when passing through a security search device; and a coating liquid including the frequency resonator therein and formed on the drafting paper.

Methods and devices for enhancing performance of a power splitter are presented. According to one aspect, the power splitter is realized via lumped elements that include inductively coupled coils. Values of the lumped elements are based on an equivalent circuit of the power splitter that includes a star topology provided by a mutual inductance connected to a first port of the power splitter and respective inductances of the inductively coupled coils modified by the mutual inductance connected between the mutual inductance and respective second and third ports of the power splitter. A coupling factor of the inductively coupled coils has a magnitude that is in a range from 0.15 to 0.45. The coupling factor is negative. Respective capacitors are connected to the ports of the power splitter. The respective capacitors include switchable capacitors.

Methods and devices for enhancing performance of a power splitter are presented. According to one aspect, the power splitter is realized via lumped elements that include inductively coupled coils. Values of the lumped elements are based on an equivalent circuit of the power splitter that includes a star topology provided by a mutual inductance connected to a first port of the power splitter and respective inductances of the inductively coupled coils modified by the mutual inductance connected between the mutual inductance and respective second and third ports of the power splitter. A coupling factor of the inductively coupled coils has a magnitude that is in a range from 0.15 to 0.45. The coupling factor is negative. Respective capacitors are connected to the ports of the power splitter. The respective capacitors include switchable capacitors.

A high frequency band pass filter with a coupled surface mount transition is provided, including a filter substrate, circuit connection elements defining input and an output elements provided on a surface of the filter substrate, electronic filter components provided on the first surface of the filter substrate, and impedance matching structures provided on the first surface of the filter substrate between the electronic filter components and the respective input and output elements. Signal connection structures are provided on an opposed surface of the filter substrate, in locations that positionally correspond to respective positions of the input and output elements. The respective signal connection elements are capacitively coupled, through a thickness direction of the filter substrate, to a respective one of the input and output elements on the opposed surface of the filter substrate without the presence of any vertical conductive structures within the filter substrate at the input and the output elements.