Yongsheng Dai

A Miniaturized and Low Insertion Loss LTCC Filter with Two Finite Transmission Zeros for Bluetooth Application

This letter outlines the design and manufacture of a miniaturized bandpass filter realized by low-temperature cofired ceramic (LTCC) technology for bluetooth applications. The bandpass filter with a central frequency of 2450 MHz and a 100 MHz passband is designed as a three-dimensional (3-D) structure based on lumped components. Experimental measurements were compared with modeling. The insertion losses in the passband (100 MHz) were less than 1.2 dB and the attenuation was more than 20 dB in the stop band. The area occupied by the filter is 1.6times0.8times0.6 mm3.

An ultra broadband 2–18GHz 6-bit PHEMT MMIC digital attenuator with low insertion phase shift

An ultra-wideband (2–18GHz) 6-bit MMIC digital attenuator has been designed. The attenuator has been fabricated with 0.5µm GaAs PHEMT process. Low insertion phase shift has been achieved over the main attenuation states. On-wafer measurement results of the developed MMIC chips in the 2–18GHz band show that the 6-bit MMIC digital attenuator has 31.5dB dynamic range stepped by 0.5dB; attenuation accuracy: +2.31dB/−0.51dB; insertion phase shift: +6.28°/−1.53° referenced insertion loss: <−5.71dB; input/output VSWR: <2.32; chip size: 2.89mm×1.22mm×0.1mm.

A miniaturized LTCC low-pass filter based on the lumped circuit model

In this paper, the design of miniaturized low-pass filter in a Low Temperature Co-fired Ceramic(LTCC) Technology is presented. The pass-band of the low-pass filter is from 900MHz to 1450MHz. The capacitor is constructed by multilayer MIM(Mental-Insulator-Mental) capacitor, and the inductor is fabricated by a narrow metal transmission line. The VSWR of input and output port is less than 1.6. The whole volume of final three-dimension model is 2.0mm×1.25mm× 0.90mm.

A miniaturized LTCC bandpass filter with low insertion loss and high image rejection within 6.5 to 7.1GHz frequency range

A low-temperature-cofired ceramic (LTCC) bandpass filter with low insertion loss and high image rejection is presented for super heterodyne microwave receiver within 6.5–7.1GHz band. By improving the filter cell structure, two transmission zeros can be generated to achieve wide-band image suppression from cascading filter cells. The presented method provides the design flexibility of locating these transmission zeros distributed in the lower and upper stopbands. To reduce insertion loss and size of the filter, a miniaturized LTCC three-stage bandpass filter with two transmission zeros in lower stopband has been implemented for experimental demonstration. The measured insertion loss is less than 1.0 dB at 6.8GHz, the measured image rejection from 5 to 5.6GHz is more than 42dB, the input/output VSWR is less than 1.5. The size of the miniaturized filter is only 2.5mm×2mm×1.2mm. The process yield of the LTCC filter is more than 90%.

A microminiature 3dB multilayer double-octave hybrid coupler using LTCC

In this paper, a low profile, high reliability, high performance 3dB multilayer hybrid coupler using LTCC is designed and manufactured. It is designed particularly for balanced power and low noise amplifiers, plus signal distribution and other applications where low insertion loss, tight amplitude and phase balance is required. In this design, high performance (VSWR of each port is less than 1.35; the isolation is more than 20dB; the amplitude balance is /spl plusmn/0.5dB; the phase balance is 90/spl plusmn/2/spl deg/; the highest power the coupler can be used in is up to 200W.) and small size (8mm/spl times/5.6mm/spl times/2mm) are gained within 6-13GHz frequency band. The operating temperature of the coupler is -55 to +85/spl deg/C.

A LTCC miniaturized broadband modified Marchand balun

A miniaturized broadband marchand balun using low temperature co-fired ceramic (LTCC) technology is proposed in this paper. Modified Marchand balun has been chosen to broaden the bandwidth, and it covers the band of 0.95-2.15 GHz. A spiral broadside coupled stripline is adopted to realize the proposed miniaturized balun, and the overall size of the LTCC balun is only 2.0mm×1.25mm×0.95mm. Measured results match well with the computer simulation. The fabricated balun with symmetric structure achieves good VSWR and insertion loss performance, as well as excellent amplitude imbalance and phase difference.

Design on antenna switch module for dual band phone (GSM/UMTS) using LTCC technology

This paper presents the results of an antenna switch module integrating a switch (SP9T) and two low-pass filters for harmonic rejection on a low temperature co-fired ceramic (LTCC) substrate. This contributes not only to reduce the size and weight, but also to shorten the development term of RF circuit and simplify the assembly process. It will be used for GSM/UMTS dual mode cellular phones. The 50-ohm in/out FEM utilized a GaAs PHEMT switch is attached to the LTCC substrate. S-parameter characterization of FEM demonstrated excellent insertion, return loss and isolation characteristics of ASM. The final three-dimension model occupied a volume of 4.5mm×3.2mm×1.4mm.

Design and implementation of an miniaturized LTCC filter with high stopband rejection

A miniaturized and high stopband rejection bandpass filter(BPF) with three finite transmission zeros is presented in this paper. The BPF with a central frequency of 3.2 GHz and 200 MHz bandwidth is implemented in a novel distributed stripline configuration using LTCC (low-temperature-cofired ceramic) technology. A distinct feature of this filter is excellent out-of-band attenuation performance. The lower skirt of the passband is very steep. There is 34.6dB attenuation at 3.0 GHz, the input/output VSWR is less than 1.4. We employ Z-shape layer to produce the lower 2 transmission zeros. By properly controlling the cross-coupling between the second and the fourth resonator, transmission zero in higher skirt of the passband will be generated. Measurement results of mass production are shown to match well with the electromagnetic simulation, which validate the proposed structure. The overall size of the filter is 4.8mm×4.2mm×1.5 mm.

A compatible multi-polarity control signals multi-octave 180/spl deg/ MMIC phase shifter without driver

Design, fabrication and characterization of a compatible multi-polarity control signals multi-octave 180/spl deg/ MMIC phase shifter with either digital or analogue control without driver have been demonstrated in this paper. The main electrical parameters of the phase shifter: low peak phase error /spl les/180/spl plusmn/6/spl deg/, low VSWR /spl les/1.7, low insertion loss variations /spl les/3.8/spl plusmn/0.7dB, over their entire operational bandwidth (4-16 GHz) and small size (4.2mm/spl times/0.64mm/spl times/0.1mm) is obtained.

Miniaturized LTCC wideband bandpass filter using lumped-element shunt LC resonators

In this letter, shunt LC resonators realized by multilayer spiral inductors and Metal-Insulator-Metal (MIM) capacitors in parallel connection are proposed to design the wideband bandpass filter (BPF) using Low Temperature Co-fired Ceramic (LTCC) technology. A distinct feature of this filter is the ingenious use of mutual coupling and broadside coupling which are introduced by the close packed elements, so as to achieve the coupling between adjacent resonators. With the assistance of the cross coupling which is implemented by a Z-shaped metal layer, a pair of transmission zeros are produced both above and below the passband.