An apparatus includes a directional coupler and an absorptive low pass filter, in which the directional coupler has a first transmission line extending from a first port to a second port and a second transmission line extending from a third port to a fourth port, the first transmission line and the second transmission line configured such that a portion of a signal travelling from the first port onto the first transmission line is coupled to the second transmission line and towards the third port. The second port is connected to the fourth port of the directional coupler via the absorptive low pass filter. When the signal is input into the first port of the directional coupler and output through the third port of the directional coupler, the signal is substantially unattenuated if the frequency of the signal is in a passband of the absorptive low pass filter.

A directional coupler arrangement, comprising: a directional coupler comprising a direct path and a first coupled port and a second coupled port; a compensation arrangement configured to provide a coupling between signals of the first coupled port and of the second coupled port; wherein the compensation arrangement is configured to improve a directivity when compared to a directivity of the directional coupler by the coupling.

Doherty power amplifiers with coupled line combiners are provided herein. In certain embodiments, a power amplifier system includes a carrier amplifier having a carrier output that provides a first radio frequency signal, a peaking amplifier having a peaking output that provides a second radio frequency signal, and a coupled line combiner that combines the first radio frequency signal and the second radio frequency signal to generate a radio frequency output signal at an output terminal. The coupled line combiner includes a first conductor line connected between the peaking output and a reference voltage, a second conductor line electromagnetically coupled to the first conductor line, a third conductor line connected between the carrier output and the reference voltage, and a fourth conductor line electromagnetically coupled to the third conductor line and connected between the output terminal and the second conductor line.

Disclosed is a capacitive non-directional coupler having a non-directional coupler printed circuit board (PCB) and a capacitive attenuator. The non-directional coupler PCB includes a coupler section configured to carry energy travelling on a main transmission line. The non-directional coupler PCB and the capacitive attenuator are configured as a capacitive voltage divider, and provide a sample of the energy on the main transmission line. Also disclosed is a method for measuring for measuring RF power using an RF power sensor having the capacitive non-directional coupler that includes with the non-directional coupler printed circuit board and the capacitive attenuator. Also disclosed is an RF power metering system that includes an RF power sensor having the capacitive non-directional coupler.

A coupled-line rat-race coupler includes four ports and four coupled-lines each composed of two metal lines. Two of the ports are respectively connected with the front ends of the two lines of the first coupled-line, and the other two ports are respectively connected with the front ends of the two lines of the second coupled-line. The two lines of the third coupled-line are short circuited and respectively connected with the back end of one line of the first coupled-line on one side and with the back end of one line of the second coupled-line on the other side. In the fourth coupled-line, one line is open at one end and short circuited at the other end with the other line, which is connected with one line of the first coupled-line and one line of the second coupled-line. The coupled-line rat-race coupler is characterized with smooth and stable output phase.

A directional coupler according to various embodiment and an electronic device having the same are provided. The directional coupler includes a first layer having at least one conductive portion, a second layer disposed adjacent to the first layer in a first direction and having at least one conductive plate corresponding to the conductive portion of the first layer, a third layer disposed adjacent to the second layer in the first direction and including an RF signal transmission line, a fourth layer disposed adjacent to the third layer in the first direction and having a conductive line wound with at least one turn, and at least one conductive via electrically connecting the at least one conductive plate of the second layer and the conductive line of the fourth layer which is wound with at least one turn.

Baluns with integrated matching networks are provided herein. In certain embodiments, a balun structure includes a first pair of coupled lines, a second pair of coupled lines and a transmission line. Additionally, a first port of the balun is connected to a reference voltage by way of a first line of the first pair of coupled lines, the transmission line, and a first line of the second pair of coupled lines. Furthermore, a second port of the balun is connected to the reference voltage by way of a second line of the first pair of coupled lines, while a third port of the balun is connected to the reference voltage by way of a second line of the second pair of coupled lines. The first port serves as an unbalanced signal terminal, while the second port and the third port serve as positive and negative signal terminals.

Examples disclosed herein relate to methods and apparatuses for a radiating structure to radiate a transmission signal, where the radiating structure incorporates reactance control elements to change a reactance of transmission lines and/or radiating unit cell elements, and a resonant coupler to isolate the transmission signal from a reactance control signal to the reactance control elements. A reactance control signal, such as a bias voltage, controls the reactance of transmission lines of the transmission array structure and/or the radiating unit cell elements so as to change the phase of the transmission signal, thereby steering a beam of the transmission signal. The reactance control elements may be incorporated into a microstrip within the transmission lines.

An optical transmission module, an optical data link, and an optical transmission system achieving a simplified matching circuit and a bias circuit with higher power efficiency. An optical transmission module including a first line, one end of which is connected to a high-frequency signal input unit and the other end of which is connected to a termination unit; a second line, one end of which is connected to an electrical-optical conversion unit and the other end of which is connected to a power supply connection unit of a DC power supply; and a coupling portion at which the first line is electromagnetically coupled to the second line. In the second line, a signal input from the high-frequency signal input unit is propagated only to the electrical-optical conversion unit due to an attenuation relationship between coupling characteristics and isolation characteristics of the first line and the second line. Alternatively, provided is an optical transmission module including a matching resistor connected in parallel to an electrical-optical conversion unit, a first capacitor preventing a direct current from flowing from a power supply connection unit of a DC power supply to the matching resistor, and a second capacitor connected in series between a high-frequency signal input unit and the matching resistor. Also provided are an optical data link and an optical transmission system.

Disclosed is a capacitive non-directional coupler having a non-directional coupler printed circuit board (PCB) and a capacitive attenuator. The non-directional coupler PCB includes a coupler section configured to carry energy travelling on a main transmission line. The non-directional coupler PCB and the capacitive attenuator are configured as a capacitive voltage divider, and provide a sample of the energy on the main transmission line. Also disclosed is a method for measuring for measuring RF power using an RF power sensor having the capacitive non-directional coupler that includes with the non-directional coupler printed circuit board and the capacitive attenuator. Also disclosed is an RF power metering system that includes an RF power sensor having the capacitive non-directional coupler.