Dual-Band Waveform Generator With Ultra-Wide Low-Frequency Tuning-Range

To achieve a compact design for low frequency tunable sound absorption, a membrane sound absorber (MSA) with nonlinear magnetic field is proposed in this paper. By employing a central iron platelet on the membrane, the MSA can be easily tuned by introducing a magnet at a distance from the platelet that can be adjusted. To investigate the low frequency properties of MSA with different magnets and iron-platelets, a series of impedance tube experiments are conducted in detail. The sample absorber has a rear cavity depth of 30 mm, three different magnets were used inside, tested results real that using a strong magnetic field can help broaden the frequency tuning range. Then, results from the MSA with five different sizes of iron plates tuned by one magnet show that the low-frequency tuning range moves to lower with the increase of the area of iron plates.

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A Dual-Band SiGe HBT Frequency-Tunable and Phase-Shifting Differential Amplifier Employing Varactor-Loaded, Stacked LC Resonators

International Journal of Microwave Science and Technology ◽

10.1155/2012/157971 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7

Author(s):

Kazuyoshi Sakamoto ◽

Yasushi Itoh

Keyword(s):

Tuning Range ◽

Frequency Tuning ◽

Phase Variation ◽

Phase Shifting ◽

Differential Amplifier ◽

Dual Band ◽

Sige Hbt ◽

Frequency Tunable ◽

Lc Resonators ◽

Frequency Phase

A dual-band SiGe HBT frequency-tunable and phase-shifting differential amplifier has been developed for the future active phased array antennas with a multiband, multibeam, and multitarget tracking operation. The amplifier uses varactor-loaded, stacked LC resonators in the design of the output circuit in order to provide frequency-tunable and phase-shifting capabilities for dual frequencies. By utilizing the varactor-loaded LC resonator, which has a variable resonant frequency and a large insertion phase variation, frequency-tunable and phase-shifting performances become available. Moreover, by using the stacked configuration, the frequency and insertion phase can be varied independently for dual frequencies. A dual-band SiGe HBT differential amplifier has achieved a lower-frequency tuning range of 0.56 to 0.7 GHz for a higher fixed frequency of 0.97 GHz as well as a higher-frequency tuning range of 0.92 to 1.01 GHz for a lower fixed frequency of 0.63 GHz. A lower-frequency phase variation of 99° and a higher-frequency phase variation of 90.3° have been accomplished at 0.63 and 0.97 GHz, respectively. This is the first report on the dual-band differential amplifier with frequency-tunable and phase-shifting capabilities.

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An Ultra-Low-Power K-Band 22.2 GHz-to-26.9 GHz Current-Reuse VCO Using Dynamic Back-Gate-Biasing Technique

Electronics ◽

10.3390/electronics10080889 ◽

2021 ◽

Vol 10 (8) ◽

pp. 889

Author(s):

Xiaoying Deng ◽

Peiqi Tan

Keyword(s):

Power Consumption ◽

Low Power ◽

Tuning Range ◽

Frequency Tuning ◽

Cmos Process ◽

Voltage Controlled Oscillator ◽

Back Gate ◽

Ultra Low Power ◽

Current Reuse ◽

K Band

An ultra-low-power K-band LC-VCO (voltage-controlled oscillator) with a wide tuning range is proposed in this paper. Based on the current-reuse topology, a dynamic back-gate-biasing technique is utilized to reduce power consumption and increase tuning range. With this technique, small dimension cross-coupled pairs are allowed, reducing parasitic capacitors and power consumption. Implemented in SMIC 55 nm 1P7M CMOS process, the proposed VCO achieves a frequency tuning range of 19.1% from 22.2 GHz to 26.9 GHz, consuming only 1.9 mW–2.1 mW from 1.2 V supply and occupying a core area of 0.043 mm2. The phase noise ranges from −107.1 dBC/HZ to −101.9 dBc/Hz at 1 MHz offset over the whole tuning range, while the total harmonic distortion (THD) and output power achieve −40.6 dB and −2.9 dBm, respectively.

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A compact low frequency dual band liquid crystal polymer antenna for VHF and UHF band applications

Materials Today Proceedings ◽

10.1016/j.matpr.2020.12.1212 ◽

2021 ◽

Vol 42 ◽

pp. 1356-1360

Author(s):

Gandu Srilekha ◽

P. Pardhasaradhi ◽

B.T.P. Madhav ◽

M. VenkateswaraRao ◽

M.C. Rao

Keyword(s):

Liquid Crystal ◽

Low Frequency ◽

Liquid Crystal Polymer ◽

Dual Band ◽

Crystal Polymer ◽

Uhf Band

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Implementation of tunable resonators in planar groove gap waveguide technology

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078721000507 ◽

2021 ◽

pp. 1-7

Author(s):

Titus Oyedokun ◽

Riana H. Geschke ◽

Tinus Stander

Keyword(s):

Printed Circuit Board ◽

Tuning Range ◽

Frequency Tuning ◽

Resonant Cavity ◽

Circuit Board ◽

Resonant Cavities ◽

Tunable Resonators ◽

Simulation Strategy ◽

Dc Bias ◽

Continuous Frequency

Abstract We present a tunable planar groove gap waveguide (PGGWG) resonant cavity at Ka-band. The cavity demonstrates varactor loading and biasing without bridging wires or annular rings, as commonly is required in conventional substrate-integrated waveguide (SIW) resonant cavities. A detailed co-simulation strategy is also presented, with indicative parametric tuning data. Measured results indicate a 4.48% continuous frequency tuning range of 32.52–33.98 GHz and a Qu tuning range of 63–85, corresponding to the DC bias voltages of 0–16 V. Discrepancies between simulated and measured results are analyzed, and traced to process variation in the multi-layer printed circuit board stack, as well as unaccounted varactor parasitics and surface roughness.

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