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.

Integration Design of Filtering Antenna With Load-Insensitive Multilayer Balun Filter

Abstract: Integration design of a filtering antenna fed by a load-insensitive multimode balun bandpass filter is proposed in this paper. The balun filter is designed and realized using multilayer structure for miniaturization. To be directly integrated into the antenna, both amplitude and phase performances of the balun filter are investigated with different complex load impedances. With insensitive responses against the load, this balun filter is utilized to design a filtering antenna as the feeding of a quasi-Yagi antenna, which is considered as a frequency-dependent differential complex load. The radiation characteristics are improved by applying a metallic shield as the package for the proposed design. To verify the design concept, an experimental filtering antenna is designed, fabricated, and measured with almost the same passband as that of the balun filter benefiting from the load-insensitive property of the latter. The simulated and measured results are presented, showing good agreement.

Electrical probe and method for measuring gaps and other discontinuities in enclosures using electrical inductance for RF shielding assessment

Abstract: An apparatus (30) locates and measures any seam or other discontinuity (18) within a metal enclosure (10) by determining the characteristic inductance of the discontinuity. A pair of probes or electrodes (40, 42) are connected via a balun (46) to a network analyzer (56). When the probes are placed on either side of the discontinuity, the network analyzer can measure the length of the discontinuity by equating the discontinuity to an inductor.

Design of an original K-band active balun with improved broadband balanced behavior

Abstract: This letter deals with the design of an active balun exhibiting a single-ended input and balanced outputs. We propose an original method, based on the determination of specific impedance for connecting the differential transistor pair to ground, which greatly improves the balanced behavior over a broadband frequency range. The usefulness of this method is demonstrated through a 180/spl deg/ power divider implemented on a 0.25-/spl mu/m SiGe BiCMOS process. According to simulations, measurements confirm a broadband well balanced behavior, since the power splitter exhibits phase and amplitude errors between the two channels less than 4/spl deg/ and 0.5dB, respectively, from 0.2 to 22 GHz. These errors are only 0.75/spl deg//0.03 dB in a 2-GHz span around 20 GHz, in accordance with our optimization goals.

A novel broadband active balun

Abstract: We have developed a new broadband active balun. It consists of series-connected common-gate FETs with the same gradient as the phase performance of the common-source FET. The active balun achieved broadband characteristics by using series-connected common gate FETs with the same gradient as the phase performance of the common-source FET. From 500 MHz to more than 10 GHz, the fabricated active balun shows a phase error of less than 5 degrees. A fabricated single balanced mixer using the proposed active balun had LO suppression of more than 40 dB over an LO frequency range of between 1 and 5 GHz.

A new planar marchand balun

Abstract: In this paper, a novel planar Marchand balun using a patterned ground plane is presented. In the new design, with a slot under the coupled lines cut on the ground plane, the even-mode impedance can be increased substantially. Meanwhile, we propose that two additional separated rectangular conductors are placed under the coupled lines to act as two capacitors so that the odd-mode impedance is decreased. Design theory and procedure are presented to optimize the Marchand balun. As an example, one Marchand balun on a double-sided PCB is designed, simulated, fabricated and measured. The measured return loss is found to be better than - 10 dB over the frequency band from 1.2 GHz to 3.3 GHz, or around 100% bandwidth. The measured amplitude and phase imbalance between the two balanced output ports are within 1 dB and 4 0 , respectively, over the operating frequency band.