Balun

About: Balun is a research topic. Over the lifetime, 5375 publications have been published within this topic receiving 52256 citations. The topic is also known as: Telephone balance unit.

Dual-Band Circularly Polarized Annular-Ring Microstrip Antenna for GNSS Applications

Abstract: A dual-band circularly polarized antenna fed by four apertures that covers the bands of GPS (L1, L2, L5), Galileo (E5a, E5b, E1, E2, L1), and GLONASS (L1, L3) is introduced. A lotus-shaped aperture is added to optimize the coupling between the microstrip lines and the rings. Three wideband planar baluns are used to achieve good axial ratio (lower than 2.1 dB in both bands) and VSWR (41.2%). The measured results of the annular-ring microstrip antenna show good performance of a dual-band operation, and they confirm the validity of this design, which meets the requirement of Global Navigation Satellite System (GNSS) applications.

Printed circuit balun

Abstract: A printed circuit balun includes a first relatively broad conductor on a first surface of a dielectric substrate which conductor first-mentioned from an unbalanced end of the balun to a point near the opposite balanced end of the balun. On the opposite or second surface of the substrate, there is provided a second conductor that has a first relatively narrow conductor portion spaced directly opposite the first-mentioned broad conductor. The second conductor also has on the second surface a second relatively broad conductor portion parallel to the narrow portion of the second conductor. The second relatively broad conductor portion of the second conductor is coupled at a point near the unbalanced end of the balun through the substrate to the first-mentiondd broad conductor on the first surface of the substrate. The narrow conductor portion of the second conductor is joined to the broad conductor portion of the second conductor near the balanced end of the balun.

Printed circuit transformer

Abstract: Circuits such as balanced diode mixers require balanced transformers. For ultrahigh frequency operation, a balanced transformer is formed as part of a printed circuit on a planar substrate of insulating material. The balanced transformer has a center-tapped winding formed by a loop of a strip transmission line having first and second coextensive elongated conductors disposed on the substrate. Preferably the first and second conductors are disposed adjacent each other on respective opposite sides of the substrate. At a first end portion of the strip transmission line, the second conductor is connected to a center tap, and at a second end portion of the strip transmission line, the first conductor is also connected to the center tap. For a balun transformer, the center tap is a ground plane provided by conductive regions disposed on the substrate. Preferably an unbalanced signal is fed into the transformer at a second winding including at least a third elongated conductor disposed on the substrate coextensive with the first and second conductors.

Package filter and combiner network

Abstract: A transceiver front end circuit includes an antenna terminal capable of being coupled to an antenna. A first balun circuit has a single input that is coupled to the antenna terminal, and a pair of balanced outputs coupled to a corresponding pair of balanced receiver inputs. The first balun circuit matches an input impedance of the pair of balanced receiver inputs and substantially phase shifts the input reflection coefficient of the pair of balanced receiver inputs by about 180-degrees. A second balun circuit has a single output coupled to the antenna terminal and a pair of balanced inputs coupled to a corresponding pair of balanced transmitter outputs. The second balun circuit matches an output impedance of the pair of balanced transmitter outputs and substantially phase shifts the output reflection coefficient of the pair of balanced transmitter outputs by about 180-degrees. The first balun circuit and the second balun circuit can be contained within a single package. A first shunt switch can be coupled across the pair of receiver inputs. A second shunt switch can be coupled across the pair of transmitter outputs.

Slot spiral antenna with integrated balun and feed

Abstract: A slot spiral (18) antenna with a planar integrated balun and feed. The slot spiral is produced using standard printed circuit techniques and comprises a dielectric substrate having a conductive layer which is etched to form the radiating slot spiral. An integrated microstrip feed (16) is included to provide a balanced feed to the slot spiral. Impedance matching is preformed between the microstrip feed and the slotline of the slot spiral to maximize energy transfer. A shallow reflecting cavity is included to limit the spiral radiation to one direction. The described antenna apparatus provides a simple, broadband spiral antenna suitable for incorporating into the skin of a moving vehicle. A covering layer may act as a dielecric lens. Outer parts of the slot spiral may be covered with a lossy absorber for termination. The feed point may be off-center with respect to the spiral.