A signal level control element comprises a substrate having conductive formations defining a substrate integrated wave-guide arrangement disposed at least partly within the substrate; the substrate integrated waveguide arrangement providing a quadrature hybrid coupler having first and second pairs of signal ports, such that a signal introduced to a port of one pair of the first and second pairs is provided with equal amplitude but a 90 degree phase difference to both ports of the other pair of the first and second pairs; in which a port of the first pair is configured to receive an input signal and the other port of the first pair is configured to provide an output signal; and termination circuitry connected to the ports of the second pair, the termination circuitry providing, for each port of the second pair, a respective termination having a variable impedance dependent upon a respective control signal.

A modulator, a manufacturing method, and a transmitting apparatus are provided, applied to the field of wireless communication technologies. The modulator includes a first modulation circuit. The first modulation circuit includes a diode and a first microstrip. The first microstrip includes a first metal wire, a second metal wire, and an intermediate medium. The first metal wire and the second metal wire are disposed in parallel on a first surface of the intermediate medium along a first straight line. A first end of the first metal wire is opposite to a second end of the second metal wire, and a first spacing area with a spacing distance equal to a first value exists between the first end of the first metal wire and the second end of the second metal wire. A second end of the first metal wire is coupled to an anode of the diode.