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

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.

An L-band SiGe HBT differential amplifier with frequency and rejection-level tunable, multiple stopband

2009 ◽  
Vol 1 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Masaki Shirata ◽  
Toshio Shinohara ◽  
Minoru Sato ◽  
Yasushi Itoh
Keyword(s):  
Bias Voltage ◽  
Frequency Tuning ◽  
Differential Amplifier ◽  
Tank Circuit ◽  
Band Frequency ◽  
Varactor Diode ◽  
Sige Hbt ◽  
Active Load ◽  
Rejection Level ◽  
L Band

An L-band frequency and rejection-level tunable SiGe HBT differential amplifier with dual stopband is presented. To achieve frequency and rejection-level tunable performance, dual LCR-tank circuit with an active load is incorporated into the design of the series feedback loops of the differential amplifier. The active load consists of a varactor diode represented as a variable C and a common-emitter transistor represented as a variable R. The frequency and rejection level can be tuned independently by controlling a cathode bias voltage of the varactor diode or a base bias voltage of the transistor. The implemented 0.35 μm SiGe HBT amplifier with dual stopband demonstrates a frequency tuning of 0.53–1.16 GHz and a rejection-level variation up to 9.5 dB. The input and output return losses are better than 17.5 and 11 dB over 0.2–1.5 GHz, respectively. The measured P1dB is+3 dBm and IIP3 is 0 dBm with Vcc = 6 V and Ic = 8 mA.

scholarly journals A Tunable Planar Balun with an Isolation Circuit Using Varactors Loaded Coupled Lines

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 401
Author(s):  
Shaojun Fang ◽  
Xiaojian Guo ◽  
Hongmei Liu ◽  
Zhongbao Wang
Keyword(s):  
Phase Difference ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Impedance Match ◽  
Flow Diagram ◽  
Coupled Lines ◽  
Mode Method ◽  
Frequency Tunable ◽  
Tunable Frequency ◽  
Planar Balun

In this paper, a frequency tunable planar balun composed of varactors loaded coupled lines (VL-CLs) is presented. By tuning the capacitances of the varactors, a wide frequency tuning range is obtained. Moreover, good impedance match, balanced output ports amplitude, and consistent output ports phase difference (PD) are maintained during the tuning. A detailed theoretical analysis using the signal flow diagram and the even-odd mode method is presented to clarify the characteristics of the proposed balun. To achieve ideal output matching and isolation for the proposed balun, a novel frequency tuned isolation circuit (IsC) is designed and connected to the balun. In theory, a frequency tuning range of 200% can be realized. In practice, due to the limited capacitances of the varactors, a prototype with a tunable frequency of 1.0 GHz ~ 2.0 GHz (66.7%) is designed, fabricated, and measured. The measured results show that more than21 dB of return loss (RL), 180° ± 1.8° of phase difference, 0.43 dB of amplitude imbalance (AP), and 22 dB of isolation are obtained at all tuning center frequencies, agreeing well with the simulated results.

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

IEEE Access ◽  
2016 ◽  
Vol 4 ◽  
pp. 3169-3181 ◽  
Author(s):  
Ibtisam A. Abbas Al-DARKAZLY ◽  
S. M. Rezaul Hasan
Keyword(s):  
Tuning Range ◽  
Frequency Tuning ◽  
Low Frequency ◽  
Dual Band ◽  
Waveform Generator

Effect of different magnets and iron-platelets on the low frequency performance of membrane sound absorber

2021 ◽  
Vol 263 (6) ◽  
pp. 342-347
Author(s):  
Junjuan Zhao ◽  
Liying Zhu ◽  
Xinyun Li ◽  
Yueyue Wang ◽  
Wenjiang Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Sound Absorption ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Low Frequency ◽  
Cavity Depth ◽  
Sound Absorber ◽  
Frequency Tunable ◽  
Compact Design ◽  
Frequency Properties

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.

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

Electronics ◽  
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.

Implementation of tunable resonators in planar groove gap waveguide technology

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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