Abstract: A slot antenna is disclosed. The slot antenna structure includes a dielectric substrate, a grounding plate and a resonator. The grounding plate is disposed over a first side of the dielectric substrate and defines a slot. The feeding strip is disposed over a second side of the dielectric substrate and opposite to the grounding plate. The resonator is coupled to the grounding plate and is disposed horizontally within the slot.

Abstract: An antenna structure includes a main radiator element, a parasitic radiator element, a feeder and at least one first high-impedance member. The parasitic radiator element is disposed in parallel with the main radiator element. The feeder is configured to electrically or electromagnetically couple the main radiator element. The at least one first high-impedance member directly contacts the parasitic radiator element and is configured to be electrically grounded.

Abstract: An antenna structure and an antenna array are disclosed. The antenna structure includes first and second feeding traces, first to fourth vias and a radiator. The first feeding trace has a first meander portion that generates a 180-degree phase change along a length thereof at an operation frequency of the antenna structure. The second feeding trace has a second meander portion that generates a 180-degree phase change along a length thereof at the operation frequency of the antenna structure. The first and second vias are respectively coupled to two opposite points of the first feeding trace with respect to the first meander portion. The third and fourth vias are respectively coupled to two opposite points of the second feeding trace with respect to the second meander portion. The radiator coupled to the first to fourth vias. The antenna array includes antenna cells each with the antenna structure.

Abstract: A phase shifter circuit and a power divider are disclosed. The phase shifter circuit provides a (90/N)-degree phase shift for a signal with two or more frequencies, where N is an integer. The phase shifter circuit includes a first inductor, a first capacitor, a second inductor and a second capacitor. The first inductor is grounded, and is coupled to the first capacitor in series. The second inductor is grounded, and is coupled to the second capacitor in series. A first node between the first capacitor and the first inductor is coupled to a node between a second node between the second capacitor and the second inductor. The power divider includes plural circuit blocks cascaded in series. Each circuit block provides a (90/N)-degree phase shift for a signal with two or more operating frequencies.

Abstract: An antenna structure has a stack of dielectric layers and metal layers. The antenna structure includes a radiator and a grounding structure. The radiator has a parasitic radiator element, a main radiator element and a ground plane element respectively in a first metal layer, a second metal layer and a third metal layer of the metal layers. The parasitic radiator element and the main radiator element are physically spaced by a first dielectric layer of the dielectric layers. The main radiator element and the ground plane element are physically spaced by a second dielectric layer of the dielectric layers. The grounding structure laterally surrounds between the main radiator element and the ground plane element for blocking electromagnetic radiation, but not between the parasitic radiator element and the main radiator element.