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-channel passband filtering system using acoustic resonators in lattice topology

Abstract: A dual-channel passband filtering system having a first, second and third balanced ports for connecting, respectively, to a first transceiver, an antenna and a second transceiver. A first lattice-type passband filter is connected between the first and the second port, and a second lattice-type passband filter is connected between the second and the third port. A phase shifter is used to match the first and second transceiver and the second port. A balun can be used for each port to convert the balanced port to a single-ended port. In each passband filter, two series resonators are use to provide two balanced ends, and two shunt resonators are connected to the series resonators in a crisscross fashion to form a differential or balanced topology. The first and second passband filters have different frequencies.

Broadband high frequency mixer

Abstract: A broadband mixer has two separate tapered ground plane microstrip baluns associated with a first signal port and two separate tapered ground plane microstrip baluns associated with a second signal port together with a frequency converter or mixer portion coupled between the baluns associated with the first and second signal ports and a third signal port. The frequency converter or mixer portion is comprised of eight diodes in a double balanced bridge arrangement having two sets of terminals associated with the first and second signal ports, each of the terminals of said two sets being separated from each of the terminals of the third signal port by a diode to electrically isolate their respective signals. The baluns associated with the first and second signal ports provide for the transformation of unbalanced input signals to balanced signals at the frequency converting diodes. Another balun coupled between the diode bridge arrangement and the third signal port provides an unbalanced signal at the third signal port in response to balanced signals at the diodes from signal inputs at the first and second signal ports. The baluns associated with the first and second signal ports are cross-connected so that their respective signals do not pass through to the opposite signal port. The circuit is reversible in that a signal may be input to or output from any signal port.

Novel slot spiral antenna designs for dual-band/multiband operation

Abstract: New applications for wireless communications are typically accompanied by a need for antennas that integrate several frequencies and functionalities under a single aperture. Different requirements for pattern, gain, and polarization at each operating frequency further complicate the design of such antennas. Novel slot spiral antenna designs for dual-band/multiband operation are introduced. Typically excited to operate in the first mode, the proposed two-arm slot spiral is redesigned to operate efficiently in the second mode and in a hybrid first/second mode for better functionality. Several key features are introduced to achieve requirements for impedance matching, pattern, and gain suitable for a specific automotive dual-band DAB/SDARS (digital audio broadcasting/satellite digital audio radio services) antenna system. Among these features are new feeding systems, a suitable mix of spiral growth rates, and a low-loss spiral arm termination. The design is accomplished using full-wave finite-element boundary integral simulations and is verified with measurements.

A silicon MMIC active balun/buffer amplifier with high linearity and low residual phase noise

Abstract: This paper describes an integrated circuit functioning as both an active balun and a buffer amplifier. The circuit has a single-ended input and balanced output with phase and amplitude balance error less than 2/spl deg/ and 1.2 dB, respectively, measured from 1.5 GHz to 1.8 GHz at 5 V supply. When supply voltage drops down to 1.5 V, its phase and amplitude balance error remains within 5/spl deg/ and 2 dB, respectively. The circuit has high-linearity (P1 dB/sub in/=5 dBm, IIP3=16.6 dBm) and low residual phase noise (<-155 dBc/Hz@100 kHz and above) which make it suitable as an active balun/buffer amplifier between LO and balanced mixer for DCS 1800 base station receiver applications. The circuit was fully integrated on a 0.25 /spl mu/m BiCMOS process.

Coplanar Dual-Band Base Station Antenna Array Using Concept of Cavity-Backed Antennas

Abstract: In this article, we propose a novel reflector-back cavity-low-band (LB)/high-band (HB) configuration for the dual-band dual-polarized base station antenna array design. The HB antennas are embedded in the opening sections of the loop radiating arms of the LB antennas. Clear and independent radiating environments are fulfilled by using two different types of reflectors (large planar reflector and back cavity). The mutual effects between the LB and HB antennas help to acquire good impedance matching and stable radiation patterns. Loop-like LB radiators work as directors in the HB, thereby effectively suppressing the side and back radiations of the HB antennas. Dual-function open slots are loaded on the ground stubs of the LB baluns, serving as impedance transformer in the LB but filtering structures in the HB. The experimental results validate that the proposed antenna array successfully covers bandwidths of 0.69–0.96 and 3.3–3.8 GHz (VSWR < 1.5) for 4G/5G applications. The port isolations are higher than 38 and 25 dB in the LB and HB, respectively. With the two independent radiating environments formed in the two bands, both LB and HB antennas exhibit stable unidirectional radiation patterns. The antenna gains and HPBWs are also satisfactory in both bands.