Electromagnetic coupler systems including built-in frequency detection, and modules and devices including such. One example of an electromagnetic coupler system include an electromagnetic coupler having an input port, an output port, a coupled port, and an isolation port, the electromagnetic coupler including a main line extending between the input port and the output port, and a coupled line extending between the coupled port and the isolation port, the electromagnetic coupler being configured to produce a coupled signal at the coupled port responsive to receiving an input signal at the input port. An adjustable termination impedance is connected to the isolation port. A frequency detector is connected to the adjustable termination impedance and to the coupled port, and configured to detect a frequency of the coupled signal and provide an impedance control signal to tune the adjustable termination impedance based on the frequency of the coupled signal.

A calibration circuit board for an antenna. The calibration circuit board may include: a first metal layer configured to be grounded; a first substrate over the first metal layer; a second substrate over the first substrate; and a plurality of couplers. Each coupler may include: a transmission line provided with an input port and an output port at both ends thereof, respectively; and a coupling line coupled with the transmission line and including two first portions respectively located at both sides of the transmission line, and a second portion connected between the two first portions. The coupling lines may be connected in series to provide a first calibration port and a second calibration port. One of the transmission lines and the coupling lines may be between the first substrate and the second substrate, and the other of the transmission lines and the coupling lines may be over the second substrate.

A directional coupler includes: a main line; a sub line; a first switch, a first end of which is directly connected to one end of the sub line and a second end of which is connected to a first signal path that extends to an isolation port (ISO), which is a first port; and a second switch, a first end of which is directly connected to another end of the sub line and a second end of which is connected to a second signal path that extends to a coupling port (CPL), which is a second port.

A directional coupler is provided that includes a primary line that transmits signals from a first terminal to a second terminal; a secondary line that gets coupled with the primary line and draws some of the signals into a third terminal; a first switching unit that switches the connection destination of the third terminal between one end of the secondary line and the other end thereof; a first impedance regulating unit that is installed in between one end of the secondary line and the ground, and that changes the impedance according to the frequency of the signals; a second impedance regulating unit that is installed in between the other end of the secondary line and the ground, and changes the impedance according to the frequency of the signals; and a resonance circuit that is installed in between the first switching unit and the third terminal, and that changes the impedance of the third terminal according to the frequency of the signals.

The disclosure relates to a hybrid orthogonal signal generator, a coil transmission front-end device, an RF coil system, and an MRI system. The hybrid orthogonal signal generator has an input end for receiving an RF signal, generates a hybrid orthogonal excitation signal on the basis of the RF signal, and provides the hybrid orthogonal excitation signal by means of an output end of the hybrid orthogonal signal generator, and comprises: a first conductor, arranged in a plane and being arc-shaped; and a second conductor having mutual inductance with the first conductor, the second conductor being connected between the input end and output end, wherein the first conductor and second conductor are parallel and arranged as mirror images of each other. The hybrid orthogonal signal generator has a compact size and is suitable for providing hybrid orthogonal excitation signals for an MRI system with a low field strength.

A coupling device includes a plurality of couplers, a first coupled output port and a second coupled output port, wherein the plurality of couplers comprise a first coupler and a second coupler that are adjacent one another, and each of the first coupler and the second coupler comprises a main line and a subline, and for each of the first coupler and the second coupler: the subline includes a first section, a second section, and a third section, wherein the second section of the subline of the first coupler has a common segment with the first section of the subline of the second coupler.

In a clock apparatus, a signal waveguide includes: a gas cell having a sealed interior; and a dipolar gas inside the sealed interior. A first apparatus is configured to provide a first electromagnetic wave through the sealed interior along a first direction. A second apparatus is configured to provide a second electromagnetic wave through the sealed interior along a second direction, in which the second direction is opposite the first direction. Also, the clock apparatus includes receiving apparatus coupled to the signal waveguide and configured to detect an amount of energy in the second electromagnetic wave passing through the dipolar gas.

An antenna array with control circuitry placed at a front of the antenna array and between the antenna elements. By locating the azimuth beamforming network control circuitry on the front of the array and between antenna elements, the antenna elements and the other components can be coupled to the control circuitry without using cables. This leads to a reduction in the number of cable connections and to a reduction in size and weight of the resulting antenna array. The ABFN control circuitry is also used to control the beams formed from each row and not from each column as is usually done.

A Docsis-MoCA coupled line directional coupler includes an input port, an output port, a coupled port, and a termination port. A first track connects the input port to the output port and a second track, which may be substantially parallel to the first track, connects the termination port to the coupled port. The first track and the second track are configured to form a variable coupling length so as to control, for instance, an isolation level between the output port and the coupled port to be less than a predetermined isolation level in a MoCA frequency band.

Examples of the disclosure include a coupler comprising an input port, an output port, a coupled port, an isolated port, a main line coupled between the input port and the output port, a coupled line coupled between the coupled port and the isolated port, and at least one capacitive element switchably coupled between at least one of the input port or the main line and at least one of the coupled port or the coupled line.