Characterization of microstrip antennas using the TLM simulation associated with a Prony‐Pisarenko method

Abstract

SUMMARYThe transmission-line matrix (TLM) method enables simulation of interior electromagnetic field propagation problems. With the use of absorbent walls, we can simulate exterior problems such as the radiaition of a microstrip antenna. The input impedance is deduced from the standing wave observed in the feedline. The radiation pattern is determined from the field over a plane located in the immediate vicinity of the antenna, using the theory of radiating apertures. However, the CPU time and memory space involved are excessive.Since the radiating structure has several resonant frequencies, it is convenient to apply classical digital signal processing techniques such as finite impulse response filtering associated with a linear prediction method. The present paper focuses on a Prony-Pisarenko method to improve on the TLM method in terms of both computation time and precision of the frequency-domain analysis of the results. In this case, overall CPU time is reduced by a factor of 2 to 3. The paper discusses the results obtained for radiation patterns. This represents a new field of application for the TLM method whose drawbacks are reduced by using appropriate signal processing methods.

Digital signal processing of time domain field simulation results using the system identification method

“…Using the Prony-Pisarenko method [7] the overall CPU time can be reduced by a factor of 2 to 3 and using the MUSIC-method [ 1 11 it can be reduced by a factor of 10 for TLM simulations. The computation time of transient analyses can be reduced by a factor of about 9 using FDTDISI for the given example of the coplanar band-reject filter.…”

Characterization of a Circular Polarization Microstrip Antenna using a Temporal Method

“…Witj the use ofso signal processing such as. Prony-Jisarerko method (PPM)X we could obtain the frequency spectruim theeinput irmpedance or the radiation pattern which charactrize the structure (2). With the PPM, a parametric method which permits to predict the non-calculated sample, it is possible to obtain the main results with less iterations than Fourier transform.…”

Modelling of microwave circuits by system identification methods

“…Prony's method allows to match a deterministic model of the circuit to the data obtained by electromagnetic field simulation [1]. Mostly it has been used in combination with full-wave analysis for reducing the computational effort in time domain analysis [2][3][4]. Time domain circuit simulation of complex distributed circuits may exhaust the available computing resources.…”

“…We use the TLM method for the simulation of the distributed sub-circuits. System identification methods have emerged as a powerful tool in recent years [1][2][3][4][5]. Prony's method allows to match a deterministic model of the circuit to the data obtained by electromagnetic field simulation [1].…”

“…Numerical robustness is achieved by using singular value decomposition (SVD) rather than direct solution of normal equations by covariance method. The number of poles required for an approximation of sufficient accuracy can be estimated by an observation of the prediction error = e = x-x or a separate eigenvalue analysis of the time domain series [3]. In TLM typically mesh widths are chosen that are smaller than 1/20th of the smallest wavelength under consideration.…”