An Integrated Two-Mode Tunable Channelized Low-Noise Active Filter

2018 ◽  
Vol 27 (06) ◽  
pp. 1850090
Author(s):  
Amin Alahyari ◽  
Massoud Dousti ◽  
Mohammad Bagher Tavakoli

In this paper, a new structure for an integrated channelized active filter is proposed. This filter can be used as a channelized bandpass filter and again as a channelized band-stop filter. This is fulfilled by using one biasing voltage. In designing a three-channel bandpass filter, a recursive differential structure is used. Moreover, by subtracting bandpass filter output from an all-pass output, the proposed three-channel band-stop filter is achieved. A wideband amplifier plays the role of an all-pass filter. In addition, to decrease the noise of this filter, a noise-canceling circuit is adopted. By using this circuit, input impedance matching is obtained simultaneously. The center frequencies of the two-mode channelized filter are 2, 4 and 6[Formula: see text]GHz. In each of them, the center frequency is controlled via two biasing voltages. The maximum center frequency shift is 450[Formula: see text]MHz. For designing the proposed circuit, GaAs 0.15[Formula: see text][Formula: see text]m technology is applied. The occupied area is [Formula: see text][Formula: see text]mm2.

Author(s):  
Shuxiang Song ◽  
Guolun Liu ◽  
Mingcan Cen ◽  
Chaobo Cai

Traditional filters usually have low Q and gain values and it is difficult to adjust their center frequencies. Moreover, it is very complicated to analyze their transmission charateristics through conventional methods. Therefore, in this paper, a tunable differential N-path bandpass filter that uses a new adjoint network method to analyze the transmission characteristics of the differential N-path structure is proposed. The filter circuit adopts a novel circuit structure consisting of two differential N-path structures, two transconductance amplifiers and an off-chip transformer. The differential structure eliminates even harmonics, the transconductance amplifier increases the circuit gain and the off-chip transformer acts as a balun, improving the filter’s Q value and achieving impedance matching. Unlike the traditional switching capacitance method used for analyzing the differential circuit structure, the method proposed in this paper does not involve complicated calculus operations. In fact, the method greatly simplifies these complex operations, and the transmission function of the circuit can be obtained through simple algebraic operations. The proposed filter was designed using TSMC 180[Formula: see text]nm CMOS process. Simulation results for a differential four-path bandpass filter formed under 1.2[Formula: see text]V supply voltage show that the gain of the filter is greater than 8.5 dB, the center frequency can be adjusted from 0.1[Formula: see text]GHz to 1[Formula: see text]GHz, the in-band insertion loss S11 is greater than 10 dB, the out-of-band IIP3 is greater than 10 dBm, the out-of-band rejection is 28 dB and the noise figure is less than 2.2 dB at [Formula: see text][Formula: see text]MHz.


Author(s):  
Darine Kaddour ◽  
Jean-Daniel Arnould ◽  
Philippe Ferrari

In this paper, a miniaturized bandpass filter for ultra-wide-band applications is proposed. It is based on the embedding of high-pass structures in a low-pass filter. A semi-lumped technology combining surface-mounted capacitors and transmission lines has been used. The filter design rules have been carried out. Furthermore, two filters having a 3-dB fractional bandwidth of 142 and 150%, centered at 0.77 and 1 GHz, respectively, have been realized for a proof of concept. Measured characteristics, in good agreement with simulations, show attractive properties of return loss (|S11| <−18 dB), insertion loss (<0.3 dB), and a maximum group delay and group delay variation of 2 and 1.3 ns, respectively. A distributed filter based on the same low-pass/high-pass approach has been also realized and measured for comparison. The size reduction reaches 85% for the semi-lumped filter, and its selectivity is improved with a shape factor of 1.3:1 instead of 1.5:1. The semi-lumped filter's drawback is related to a smaller rejection bandwidth compared to the distributed one. To improve the high-frequency stopband, an original technique for spurious responses suppression based on capacitively loaded stubs has been proposed. Even if the performances do not reach that obtained for the distributed approach, with this technique spurious responses are pushed until eight times the center frequency. A sensitivity study vs. critical parameters has also been carried out, showing the robustness of the design.


2016 ◽  
Vol 6 (6) ◽  
pp. 1294-1296
Author(s):  
N. Soltani

A monolithic tunable low noise active bandpass filter is presented in this study. Biasing voltages can control the center frequency and quality factor. By keeping the gain constant, the center frequency shift is 300 MHz. The quality factor can range from 90 to 290 at the center frequency. By using a noise cancelling circuit, noise is kept lower than 2.8 dB. The proposed filter is designed using MMIC technology with a center frequency of 2.4 GHz and a power consumption of 180 mW. ED02AH technology is used to simulate the circuit elements.


Author(s):  
Sanae Azizi ◽  
Mustapha El Halaoui ◽  
Abdelmoumen Kaabal ◽  
Saida Ahyoud ◽  
Adel Asselman

<p>In this paper, the bandwidth enhancement of bandpass filter (BPF) is proposed by utilizing defected microstrip structure (DMS). The initial micro strip BPF which is designed to have the bandwidth 1GHz with the center frequency of 3.5GHz is deployed on FR4 Epoxy dielectric substrate with overall size and thickness of 14mm x 24mm and 1.6mm, respectively. The proposed filter consists of two parallel coupled lines centred by ring-shaped, to enhance the bandwidth response, an attempt is carried out by applying DMS on the ligne center with a ring-shaped of initial filter. Here, the proposed DMS is constructed of the arrowhead dumbbell. Some parametrical studies to the DMS such as changing to obtain the optimum geometry of DMS with the desired bandwidth response. From the characterization result, it shows that the utilization of DMS on to the microstrip ligne of filter has widened 3dB bandwidth response up to 1.8GHz ranges from 2.55GHz to 4.35GHz yielding an enhanced wideband response for various wideband wireless applications.</p>


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2853
Author(s):  
Satheeshkumar Palanisamy ◽  
Balakumaran Thangaraju ◽  
Osamah Ibrahim Khalaf ◽  
Youseef Alotaibi ◽  
Saleh Alghamdi

In this paper, a compact bandpass filter with improved band stop and band pass characteristics for wireless applications is built with four internal conductive poles in a single resonating cavity, which adds novel quad-resonating modes to the realization of band pass filter. This paper covers the design and testing of the S-band combline coaxial cavity filter which is beneficial in efficient filtering functions in wireless communication system design. The metallic cavity high Q coaxial resonators have the advantages of narrowband, low loss, better selectivity and high potential for power handling, as compared to microstrip filter in the application to determine the quality factor of motor oils. Furthermore, the tuning of coupling screws in the combline filter allows in frequency and bandwidth adjustments. An impedance bandwidth of 500 MHz (fractional bandwidth of 12.8%) has been achieved with an insertion loss of less than 2.5 dB and return loss of 18 dB at the resonant frequency. Four-pole resonating cavity filters have been developed with the center frequency of 4.5 GHz. Insert loss at 0 dB and estimated bandwidth at 850 MHz and a quality factor of 4.3 for the band pass frequencies between 4 and 8 GHz is seen in the simulated result.


Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 195 ◽  
Author(s):  
Ki-Hun Lee ◽  
Eun-Seong Kim ◽  
Jun-Ge Liang ◽  
Nam-Young Kim

In this study, the proposed bandpass filter (BPF) connects an interdigital and a spiral capacitor in series between the two symmetrical halves of a circular intertwined spiral inductor. For the mass production of devices and to achieve a higher accuracy and a better performance compared with other passive technologies, we used integrated passive device (IPD) technology. IPD has been widely used to realize compact BPFs and achieve the abovementioned. The center frequency of the proposed BPF is 1.96 GHz, and the return loss, insertion loss and transmission zero are 26.77 dB, 0.27 dB and 38.12 dB, respectively. The overall dimensions of BPFs manufactured using IPD technology are 984 × 800 μ m 2 , which is advantageous for miniaturization and integration.


2018 ◽  
Vol 7 (3.34) ◽  
pp. 421
Author(s):  
Mrs. S. Jalaja ◽  
Dr V. Prithivirajan ◽  
K Gajalakshimi ◽  
S Chitra ◽  
R Nithya

The design and simulation of coplanar waveguide (CPW) bandpass filter (BPF) has been described in this paper. It mainly focuses on Defected Ground Structure (DGS), where U-shaped DGS with open stub in transmission line has been introduced. By etching the DGS pattern in ground and transmission will change the distribution of inductance and capacitance to produce filtering effect. This paper also discusses about the influence of geometrical parameter l for the improvement in the frequency response of bandpass filter. As increasing the dimension of the geometric parameter l shift the center frequency to the higher frequencies. This filter offers a bandwidth of 1.65 GHz with passband ranging from 2.1 GHz to 3.75 GHz with a stopband rejection is about -28 dB.  


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Ying Chen ◽  
Jianwei Cheng ◽  
Chaowu Liang

To date, little research has been carried out on the integration of switchable and diversified functionalities into a single metamaterial in the terahertz (THz) range. Here, a hybrid vanadium dioxide (VO2) metamaterial was designed with switchable properties of band-pass filter and band-stop filter in the frequency range of 0.3–1.6 THz. Simulations demonstrated that under TE polarization, the proposed system acted as band-stop filter with the center frequency of 0.95 THz when VO2 is in the insulating state. Upon the transformation of VO2 into the metallic state, the proposed system behaved as a band-pass filter with a transmittance of >80%. The physical mechanism of the band-pass/band-stop conversion was examined by analyzing the surface current distribution of the designed device. The switchable characteristics of this structure can enable its wide application in tunable THz functional components such as amplitude modulators, polarization control, and intelligent switches.


Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 219
Author(s):  
Tae-Hyeon Lee ◽  
Ki-Cheol Yoon ◽  
Kwang Gi Kim

A stepped impedance resonator (SIR) is suitable for designing a dual-band bandpass filter (BPF) that can be adjusted to reject spurious bands. A BPF is proposed using an SIR T-shaped meander line and folded structure. The BPF mainly comprises a meander line, a folded structure, and a T-shaped line. A novel BPF is used for the T-shaped line, which operates as a band-stop filter connecting to the center of the BPF. As a result, the complete BPF enables dual-band operation. The insertion and return losses of the first frequency passband (f01) are 0.024 and 17.3 dB, respectively, with a bandwidth of 46% at a center frequency of 2.801 GHz (2.2–3.48 GHz). The insertion and return losses of the second frequency passband (f02) are 0.026 and 17.2 dB, respectively, with a bandwidth of 10% at a center frequency of 4.351 GHz (4.13–4.55 GHz). The proposed BPF provides low loss, a simple structure, and a small size of only 4.29 × 4.08 mm, and it can be integrated into mobile communications systems.


Author(s):  
Linh Ta Phuong ◽  
Bernard Journet ◽  
Duong Bach Gia

<p>In satellite technology, the communication between space segment and ground segment plays a vital role in the success of the mission. This paper is targeted at study, design and fabrication of a microwave active filter for the receiver front-ends using coupled line filter structure, which can be applied to the nanosatellite’s communication subsystem. The whole active filter module is a combination of a microstrip bandpass filter and a preceding two-stage wideband low noise amplifier using FET devices. The proposed module operates in the frequency range of 2 - 2.4 GHz, which can be divided to 10 frequency slots of about 40 MHz for each. These frequency slots will be used for the S-band multi-frequency receiving function of the ground station, as well as the nanosatellite. The simulated and measured results of this active filter configuration are presented.</p>


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