CiteULike: dcastros structure

A novel uniplanar compact PBG structure for filter and mixer applications

Fei-Ran Yang — 2008-05-10T00:03:34-00:00

Microwave Symposium Digest, 1999 IEEE MTT-S International, Vol. 3 (1999), pp. 919-922 vol.3.

A novel lowpass filter with a uniplanar, compact photonic band-gap structure etched in the ground plane has been proposed and demonstrated. This new filter has a deep attenuation and spurious-free response. A drain mixer using this novel filter suppresses the LO leakage by over 10 dB compared to a reference mixer with a conventional filter

A novel periodic electromagnetic bandgap structure for finite-width conductor-backed coplanar waveguides

Shau-Gang Mao — 2008-05-09T23:55:57-00:00

Microwave and Wireless Components Letters, IEEE, Vol. 11, No. 6. (2001), pp. 261-263.

The one-dimensional (1-D) periodic electromagnetic bandgap (EBG) structure for the finite-width conductor-backed coplanar waveguide (FW-CBCPW) is proposed. Unlike the conventional EBG structures for the microstrip line and the coplanar waveguide (CPW), which are typically placed on one of the signal strips and the ground plane, this EBG cell is etched on both the signal strip and the upper ground plane of FW-CBCPW resulting in a novel circuit element. The equivalent circuit is also used to model the EBG cell. Measured and full-wave simulated results show that the cell exhibits remarkable stopband effect. The low-pass filter with lower cutoff frequency and wider rejection bandwidth is constructed from a serial connection of the EBG cells. The effect of back metallization on the guiding characteristic is also discussed. Compared to the published EBG cells, the proposed structure has the advantages of relative flexibility, higher compactness, lower radiation loss, and easier integration with the uniplanar circuits

Miniature low-loss CPW periodic structures for filter applications

J Sor — 2008-05-09T16:40:15-00:00

Microwave Theory and Techniques, IEEE Transactions on, Vol. 49, No. 12. (2001), pp. 2336-2341.

Several novel periodic structures for coplanar waveguides are presented. The proposed structures exhibit low insertion loss in the passband, simple fabrication, and slow-wave characteristics. These structures are applied to realize miniature low-pass filters one-tenth the size of conventional filters, with spurious-free response and deep attenuation levels using only three cells

Practical applications of metamaterial-based structures in microwave systems

CA Allen — 2008-04-15T18:08:16-00:00

Microwave Conference, 2007. European (2007), pp. 400-403.

In this paper, metamaterial-based transmission lines will be discussed, with a focus placed on how these structures can be utilized in microwave systems. The different devices necessary for a basic dual-band receiver will be discussed and it will be shown how these dual-band components can be realized using metamaterial-based structure. Also, two different types of two-dimensional beam scanning systems will be introduced that utilize both one and two dimensional metamaterial-based structures.

Dual structure of composite right/left-handed transmission line

Xin Hu — 2007-11-07T07:53:03-00:00

Journal of Zhejiang University - Science A, Vol. 7, No. 10. (23 October 2006), pp. 1777-1780.

Abstract A dual structure of composite right/left handed (CRLH) transmission line (TL) is analyzed in which an inductance L R is in parallel with a capacitance C L and a shunt capacitance C R is in series with an inductance L L. Both the distributed and lumped cases are considered. The dispersion diagram and transmission properties of the dual CRLH TL are given and compared with those of a standard CRLH TL. Contrary to the frequency response of a standard CRLH TL, a dual CRLH TL has a left-handed (negative phase shift) band at higher frequencies and a right-handed (positive phase shift) band at lower frequencies. A novel dual-band balun is presented as an application.

A new broadband differential phase shifter fabricated using a novel CRLH structure

Yong-Zhuo Zou — 2007-11-07T07:47:38-00:00

Journal of Zhejiang University - Science A, Vol. 8, No. 10. (29 October 2007), pp. 1568-1572.

Abstract Broadband phase shifters are mostly proposed and fabricated based on the scheme proposed by Shiffman, which uses a coupled line with far ends connected together and a uniform transmission line to give a differential phase shift. Based on the unique dispersion property of the composite right/left-handed (CRLH) metamaterial structure, a new configuration is presented in this paper for fabricating the broadband differential phase shifter, which employs a novel CRLH metamaterial structure as one of the differential phase-shift arms, instead of the conventional coupled line. The new circuit can achieve a phase shift of 90� in an operational bandwidth as broad as one octave and its phase deviations are quite small. An original design of the novel broadband phase shifter is presented, in which the artificial CRLH structure was implemented by microstrip quasi-lumped elements. Both the simulated and measured results of the 90� broadband differential phase shifter are presented.

Arbitrarily dual-band components using simplified structures of conventional CRLH TLs

Xian Lin — 2007-11-05T20:33:09-00:00

Microwave Theory and Techniques, IEEE Transactions on, Vol. 54, No. 7. (2006), pp. 2902-2909.

Microwave components with nonlinear phase responses are developed using a simplified composite right/left-handed (CRLH) transmission-line (TL) structure without the series capacitance or the shunt inductance. Using such a simplified CRLH structure, arbitrarily dual-band microstrip components have been realized in compact sizes such as a quarter-wavelength short-circuited stub and dual- band branch-line couplers. Simulation and measurement results are given to demonstrate the efficiency and good performance of the proposed components. For the quarter- wavelength short-circuited stub based on the simplified CRLH-TL structure without the series capacitance, it has been shown that the insertion loss is less than -0.1dB. For the arbitrarily dual-band branch-line coupler, experiment results exhibit that S/sub 21/ and S/sub 31/ are larger than -3.6dB, the isolations are smaller than -30dB, the return losses are smaller than -20dB, and the phase differences are within 90/spl deg//spl plusmn/1.8/spl deg/.

Dispersion analysis of a microstrip-based negative refractive index periodic structure

A Grbic — 2007-11-05T20:31:12-00:00

Microwave and Wireless Components Letters, IEEE, Vol. 13, No. 4. (2003), pp. 155-157.

We present the complete band structure of a negative refractive index metamaterial based on the concept of dual transmission lines. The metamaterial is a two-dimensional (2-D) microstrip periodic structure that has cell dimensions much smaller than the wavelength of operation. It can therefore be considered as an effective medium. First, the dispersion characteristics of the metamaterial are explained by way of a 2-D loaded transmission line representation. Subsequently, full-wave analysis is utilized to reveal additional modes that can be excited in the metamaterial.