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.

Compact low-loss microwave balun

Abstract: A microwave balun is constructed by combining a four-transmission-line branch-line coupler with a single-transmission-line delay element This construction results in a simplified, compact arrangement for combining first and second signals applied to respective first and second ports, phase shifted by 180°, and providing the combined signal at a third port The balun is a reciprocal device and may be operated in reverse with a signal applied to the third port to obtain outputs at the first and second ports

Low-temperature cofired ceramic LC filters for RF applications [Applications Notes]

Abstract: Over the past few years, a great amount of effort has been spent on LTCC filters or related research [21]?[28]. Some of these components have more advanced functionalities, such as a combination of filter and balun, or a complete front-end module with balun, filter, and matching network. At the same time, advanced methodologies have also been developed to design these components [29]. All the enjoyment of miniaturized RF components or modules is due to the promising three-dimensional design flexibility of LTCC technology. It is expected that a variety of functionally complex components will be continuously available on the market such that the cost and size of the overall wireless terminal can be further reduced. Various aspects of designing miniaturized LTCC LC filters have been briefly discussed here. Conventional coupled LC resonators are commonly used in LTCC filters for RF applications because of their compact size advantage. The shunted parallel resonator in this type of filter can be realized directly as a lumped-element or distributed quarter- wavelength stripline with or without loaded capacitors. Filters with distributed resonators in general have better passband insertion loss performance. Moreover, there are many ways to improve the rejection performance in an LTCC filter design; for example, by modifying the resonators or admittance inverters so as to introduce transmission zeros at the stopband. It was demonstrated, through a design example, that by making use of the flexibility of LTCC technology, a compact LC bandpass filter can be realized for various RF applications.

A differential 4-path highly linear widely tunable on-chip band-pass filter

Abstract: A passive switched capacitor RF band-pass filter with clock controlled center frequency is realized in 65nm CMOS. An off-chip transformer which acts as a balun, improves filter-Q and realizes impedance matching. The differential architecture reduces clock-leakage and suppresses selectivity around even harmonics of the clock. The filter has a constant −3dB bandwidth of 35MHz and can be tuned from 100MHz up to 1GHz. IIP3 is better than 19dBm, P 1dB =2dBm and NF≪5.5dB at P diss =2mW to 16mW.

A Wideband SiGe BiCMOS Frequency Doubler With 6.5-dBm Peak Output Power for Millimeter-Wave Signal Sources

Abstract: This paper presents a balanced frequency doubler with 6.5-dBm peak output power at 204 GHz in 130-nm SiGe BiCMOS technology ( $f_{T}/f_{\max }=210$ /250 GHz). To convert the single-ended input signal to a differential signal for balanced operation, an on-chip transformer-based balun is employed. Detailed design procedure and compensation techniques to lower the imbalance at the output ports, based on mixed mode S parameters are proposed and verified analytically and through electromagnetic simulations. The use of optimized harmonic reflectors at the input port results in a 2-dBm increase in output power without sacrificing the bandwidth of interest. The measured conversion loss of the frequency doubler is 9 dB with 6-dBm input power at 204-GHz output. The measured peak output power is 6.5 dBm with an on-chip power amplifier stage. The 3-dB output power bandwidth is measured to be wider than 50 GHz (170–220 GHz). The total chip area of the doubler is 0.09 mm2 and the dc power consumption is 90 mW from a 1.8-V supply, which corresponds to a 5% collector efficiency.

A Tapped Stepped-Impedance Balun With Dual-Band Operations

Abstract: This letter presents the design of a dual-band balun using tapped stubs and stepped-impedance structures By adjusting the impedances of the tapped stubs properly, the two output signals of the balun are out-of-phase at the two operating frequencies which is essential for the balun operation Meanwhile, the stepped-impedance structure is designed to satisfy the dual-band matching condition at the input port Closed form design equations are derived using the even-odd mode method Based on these equations, a microstrip balun on Rogers' duroid/RT 5880 substrate operating at 245 GHz/525 GHz is designed, fabricated, and measured The measurement results verify the dual-band operations of the balun Finally, the impedance transformation property of the proposed dual-band balun is discussed