An electronic device includes a radiator of a first antenna and a radiator of a second antenna, the radiator of the first antenna includes a first branch and a second branch, and the second branch is disposed between the first branch and the radiator of the second antenna. A gap is between the first branch and the second branch, and a gap is between the second branch and the radiator of the second antenna. Also included is a first matching module, a first capacitor, and a feeding portion. A first end of the first matching module is connected to the second branch, a second end of the first matching module is connected to the feeding portion, a first end of the first capacitor is connected to the first branch, and a second end of the first capacitor is connected between the first matching module and the feeding portion.

An antenna tuning circuit is disclosed. The antenna tuning circuit is configured to make multiple estimates on an antenna impedance at an antenna port and determine an optimum tuning state for antenna tuning based on the antenna impedance estimates. The antenna tuning circuit may be further configured according to various embodiments of the present disclosure to minimize impedance estimation error, reduce magnitude and/or phase disturbance during antenna tuning, and extrapolate antenna impedance estimates for both transmit and receive frequencies. As a result, the antenna tuning circuit can accomplish autonomous antenna tuning optimization to thereby improve transmit and receive performance in a wireless communication device.

An antenna tuning circuit is disclosed. The antenna tuning circuit is configured to make multiple estimates on an antenna impedance at an antenna port and determine an optimum tuning state for antenna tuning based on the antenna impedance estimates. The antenna tuning circuit may be further configured according to various embodiments of the present disclosure to minimize impedance estimation error, reduce magnitude and/or phase disturbance during antenna tuning, and extrapolate antenna impedance estimates for both transmit and receive frequencies. As a result, the antenna tuning circuit can accomplish autonomous antenna tuning optimization to thereby improve transmit and receive performance in a wireless communication device.

A wireless device includes at least one slim radiating system having a slim radiating structure and a radio-frequency system. The slim radiating structure includes one or more booster bars. The booster bar has slim width and height factors that facilitate its integration within the wireless device and the excitation of a resonant mode in the ground plane layer, and has a location factor that enables it to achieve the most favorable radio-frequency performance for the available space to allocate the booster bar. The at least one slim radiating system may be configured to transmit and receive electromagnetic wave signals in one or more frequency regions of the electromagnetic spectrum.

A 5.sup.th generation (5G) or pre-5G communication system for supporting a higher data transfer rate than 4.sup.th generation (4G) communication systems such as long term evolution (LTE). An apparatus for radiating a signal in a wireless communication system may include: a power amplifier; a sub array including a plurality of antenna elements; and filter circuitry configured to transfer an output signal of the power amplifier to the sub array and including an input end and an output end. The filter circuitry may include: a first impedance matching circuit connected with the power amplifier; a second impedance matching circuit connected with the sub array; and a plurality of filters coupled in parallel to each of the first impedance matching circuit and the second impedance matching circuit. An impedance of the input end is matched with a sum of an impedance of the plurality of filters and an impedance of the first impedance matching circuit. An impedance of the output end is matched with a sum of the impedance of the plurality of filters and an impedance of the second impedance matching circuit.

A 5.sup.th generation (5G) or pre-5G communication system for supporting a higher data transfer rate than 4.sup.th generation (4G) communication systems such as long term evolution (LTE). An apparatus for radiating a signal in a wireless communication system may include: a power amplifier; a sub array including a plurality of antenna elements; and filter circuitry configured to transfer an output signal of the power amplifier to the sub array and including an input end and an output end. The filter circuitry may include: a first impedance matching circuit connected with the power amplifier; a second impedance matching circuit connected with the sub array; and a plurality of filters coupled in parallel to each of the first impedance matching circuit and the second impedance matching circuit. An impedance of the input end is matched with a sum of an impedance of the plurality of filters and an impedance of the first impedance matching circuit. An impedance of the output end is matched with a sum of the impedance of the plurality of filters and an impedance of the second impedance matching circuit.

Systems and methods for tuning multiplexer filters are disclosed. In one aspect, a multiplexer includes a first filter coupled to a common node, the first filter configured to pass a first band, a second filter coupled to the common node, the second filter configured to pass a second band, and at least one electrical component configured to generate a notch at a frequency between the first band and the second band.

An antenna apparatus includes a radiation shield between an antenna element and at least one radio frequency integrated circuit (RFIC) coupled to the antenna element. An antenna substrate includes a first dielectric layer having opposite first and second surfaces, and a first metallization layer attached to the second surface to form a ground plane. A base substrate includes at least one second dielectric layer having opposite third and fourth surfaces, and a second metallization layer having a first side attached to the third surface and a second side attached to the first metallization layer to form the radiation shield. The RFIC is RF coupled to the antenna element through at least one via extending through the base substrate and a coupling element within aligned openings of the first and second metallization layers.

A user equipment (UE) is provided that includes an antenna switch array for demultiplexing a reference signal sequentially to each antenna in a plurality of antennas. While the antenna switch array selects an antenna, the UE measures a reflection coefficient for the antenna. The UE then tunes the antenna responsive to the reflection coefficient measurement.

A user equipment (UE) is provided that includes an antenna switch array for demultiplexing a reference signal sequentially to each antenna in a plurality of antennas. While the antenna switch array selects an antenna, the UE measures a reflection coefficient for the antenna. The UE then tunes the antenna responsive to the reflection coefficient measurement.