The invention discloses a
transmission line, a leaky-wave antenna
multiplexing device and a
beam scanning method thereof. The device comprises a
dielectric substrate, a
metal strip and a
metal floorboard positioned on the front and back surfaces of the
dielectric substrate, and periodically alternatively arranged capacitors and variable
capacitance diodes for connecting the
metal floorboard and the metal strip via the through holes. The metal strip comprises gradient
microstrip line structures at two ends and an
artificial surface plasmon structure positioned therebetween. When the
capacitance value of the variable
capacitance diode is identical with that of the
fixed capacitor, the
surface impedance of the device is identical, and thus the function of the
transmission line is achieved; when the capacitance value of the variable capacitance
diode is not identical with that of the
fixed capacitor, the
surface impedance of the device is periodically modulated, and thus the
radiation function of the leaky-wave antenna is achieved.
Voltage is used as a regulation means, and
fixed frequency beam scanning can be achieved along with the change of the
voltage; the device is simple to manufacture, convenient to operate and prone to integrate; only a photoetching step is needed, so that cost is saved, and
machining errors caused by a multi-layer structure are avoided.