A metal body antenna having loop type radiation elements in which a housing unit is used as an antenna includes a radiation element supplied with a signal from a feeding power port, a ground coupled to the radiation element by loop coupling and in which an induction current is generated, and a frame bezel unit having an open end part separated from the ground by a dielectric and a gap. The frame bezel unit having the open end part supplied with an electric current induced into the ground is connected, and the metal body antenna operates in a wideband in multiple bands having an electrical length of a half wavelength. Accordingly, the bezel unit of a frame unit is effectively used and all of the Penta bands (i.e., GSM850, EGSM, DCS, PCS, and W2100) used in mobile phones is satisfied through a wideband multi-antenna structure having a small radiation loss.

A capacitor circuit includes a first capacitor bank and a second capacitor bank. The first capacitor bank includes p switch-capacitor circuits connected to each other in parallel, where p is a natural number of 2 or more, wherein at least two switch-capacitor circuits among the p switch-capacitor circuits have mutually different capacitance values based on a first weight. The second capacitor bank includes q switch-capacitor circuits connected to each other in parallel, where q is a natural number greater than p, wherein at least two of the q switch-capacitor circuits have mutually different capacitance values based on a second weight different from the first weight.

A reconfigurable antenna system is described which combines active and passive components used to impedance match, alter the frequency response, and change the radiation pattern of an antenna. Re-use of components such as switches and tunable capacitors make the circuit topologies more space and cost effective, while reducing complexity of the control signaling required. Antenna structures with single and multiple feed and/or ground connections are described and active circuit topologies are shown for these configurations. A processor and algorithm can reside with the antenna circuitry, or the algorithm to control antenna optimization can be implemented in a processor in the host device.

A reconfigurable antenna system is described which combines active and passive components used to impedance match, alter the frequency response, and change the radiation pattern of an antenna. Re-use of components such as switches and tunable capacitors make the circuit topologies more space and cost effective, while reducing complexity of the control signaling required. Antenna structures with single and multiple feed and/or ground connections are described and active circuit topologies are shown for these configurations. A processor and algorithm can reside with the antenna circuitry, or the algorithm to control antenna optimization can be implemented in a processor in the host device.

A THz device includes: an antenna electrode capable of transmitting and receiving a THz wave to free space; first transmission lines capable of transmitting the THz wave, the first transmission lines respectively connected to the antenna electrodes; an active element of which a main electrode is connected to each of the first transmission lines; second transmission lines capable of transmitting the THz wave, the second transmission lines connected to the first active device; pad electrodes respectively connected to the second transmission lines; and a low-pass filter with respect to the THz wave, the low-pass filter connected to the pad electrodes, wherein impedance matching of between the antenna electrode and the active element is performed by an impedance conversion of the first transmission lines. The THz device is capable of the high-efficiency matching between the active element and the antenna due to the impedance conversion effect of the transmission line.

A THz device includes: an antenna electrode capable of transmitting and receiving a THz wave to free space; first transmission lines capable of transmitting the THz wave, the first transmission lines respectively connected to the antenna electrodes; an active element of which a main electrode is connected to each of the first transmission lines; second transmission lines capable of transmitting the THz wave, the second transmission lines connected to the first active device; pad electrodes respectively connected to the second transmission lines; and a low-pass filter with respect to the THz wave, the low-pass filter connected to the pad electrodes, wherein impedance matching of between the antenna electrode and the active element is performed by an impedance conversion of the first transmission lines. The THz device is capable of the high-efficiency matching between the active element and the antenna due to the impedance conversion effect of the transmission line.

A stray capacitance is generated between an antenna element and a ground electrode. A capacitance detection circuit detects the stray capacitance. An antenna matching circuit, is provided along a wireless communication signal path, which is a transmission path between the antenna element and a feeder circuit. A feedback control circuit transmits a control signal to the variable matching circuit on the basis of a detection result of the capacitance detection circuit in accordance with the stray capacitance. The capacitance detection circuit includes a constant current source and a timing circuit to measure the time taken to charge the antenna from the constant current source and for the voltage to reach a predetermined voltage.

A stray capacitance is generated between an antenna element and a ground electrode. A capacitance detection circuit detects the stray capacitance. An antenna matching circuit, is provided along a wireless communication signal path, which is a transmission path between the antenna element and a feeder circuit. A feedback control circuit transmits a control signal to the variable matching circuit on the basis of a detection result of the capacitance detection circuit in accordance with the stray capacitance. The capacitance detection circuit includes a constant current source and a timing circuit to measure the time taken to charge the antenna from the constant current source and for the voltage to reach a predetermined voltage.

An electronic device is provided. The electronic device includes a housing including a first metallic member, a second metallic member, and a nonconductive segmenting part located between an end of the first metallic member and an end of the second metallic member, a ground member, a wireless communication circuit connected to a first point of the first metallic member through a first electrical path and connected to a second point of the first metallic member through a second electrical path, a first conductive pattern electrically connected to the first electrical path, a second conductive pattern electrically connected to the second electrical path, a first electrical variable element electrically connected between the first electrical path and the ground member, and a second electrical variable element electrically connected between the second metallic member and the ground member.

An electronic device includes a first antenna radiator configured to transmit or receive a signal of a first frequency band and a signal of a second frequency band, a second antenna radiator configured to transmit or receive the signal of the second frequency band, a matching circuit mismatched with the second antenna radiator in the first frequency band and matched with the second antenna radiator in the second frequency band, a radio frequency circuit electrically connected to the first antenna radiator and the second antenna radiator, and a processor configured to control the RF circuit such that the signal of the second frequency band is transmitted or received through the first antenna radiator and the second antenna radiator in a multi-input multi-output mode or such that the signal of the first frequency band is transmitted or received through the first antenna radiator in a single input single output mode.