Transmission line microwave apparatus including at least one non-reciprocal transmission line part between two parts

A transmission line microwave apparatus including a microwave transmission line constituted by cascade-connecting at least one unit cell between first and second ports,

• wherein said unit cell includes a series branch circuit equivalently including a capacitive element, a shunt branch circuit equivalently including an inductive element, and at least one nonreciprocal transmission line part,
• wherein the nonreciprocal transmission line part is made of a material that is magnetized by one of spontaneous method and magnetization method by an external magnetic field so as to have gyrotropic characteristic by being magnetized in a magnetization direction different from a propagation direction of a microwave, and the nonreciprocal transmission line part has an asymmetric structure with respect to a plane formed by the propagation direction and the magnetization direction, and
• wherein each unit cell of the microwave transmission line has such a circuit configuration that the microwave transmission line has a predetermined propagation constant in a dispersion curve that represents a relation between an operating frequency of a microwave signal inputted to the microwave transmission line, and the propagation constant of the microwave transmission line so that a propagation constant in a forward direction and a propagation constant in a backward direction have mutually different nonreciprocal phase characteristics.

The transmission line microwave apparatus as claimed in 21, further a controller for controlling an electromagnetic field distribution of the microwave signal on the microwave transmission line,

• wherein, when a microwave signal propagates in a propagation direction from the first port to the second port in the microwave transmission line at the operating frequency, said controller controls the electromagnetic field distribution of the microwave signal on the microwave transmission line so as to radiate a microwave signal of a radiation pattern that has at least one beam of the following:
• (a) a beam of a forward leaky wave having a direction inclined from the propagation direction,
• (b) a beam of a backward leaky wave having a direction inclined from a direction opposite to the propagation direction, and
• (c) a beam of a leaky wave having a direction substantially perpendicular to the propagation direction,
• wherein the transmission line microwave apparatus operates as a leaky wave antenna apparatus.

A transmission line antenna apparatus comprising:

• a substrate that is magnetized by one of spontaneously method and magnetization method by an external magnetic field and has a ground conductor on a back surface thereof;
• a microstrip line formed on the substrate;
• a plurality of capacitors that separate the microstrip line into a plurality of line parts and connect mutually adjacent line parts of the plurality of separated line parts;
• a plurality of short-circuit stub conductors that connect the line parts to the ground conductor;
• and
• a controller for forming a main beam that uses a leaky wave leaked from the transmission line as a radiation wave, by inputting a microwave signal to at least one of one end and another end of the transmission line, making the transmission line operate as one of a forward wave transmission line and a backward wave transmission line at a predetermined operating frequency, and controlling at least one of an amplitude and a phase of the inputted microwave signal with utilizing nonreciprocal characteristic of the transmission line.