Efficient analysis of conformal antenna structures with multiple layers

A systematic way to set up the dyadic Green’s function for multilayer structures using a full-wave equivalent circuit (FWEC) in curvilinear coordinate systems has been presented. The general formulation has been given in the first part of this contribution. Then, an application of the method has been shown for the case of a multilayered cylindrical microstrip line. The results, computed with the discrete mode matching method (DMM), have been validated with simulations done with Ansoft HFSS. The agreement between the simulations is very good, especially if the appropriate edge condition is used in the DMM formulation

Fast analysis of flush-mounted cylindrical microstrip structures

This paper presents the application of the discrete mode matching (DMM) method to analyze microstrip lines and antennas flush-mounted on cylindrical substrates. The DMM is well suited to the analysis of multilayered structures, since the fields must be calculated only at the interfaces between the dielectric layers, so that merely a one-dimensional discretization is needed to analyze cylindrical microstrip structures. The analysis is based on the Green’s function in the spectral domain, which is calculated by using a full-wave equivalent circuit. In order to demonstrate the method, two structures are analyzed: a singly-layered conformal microstrip antenna, and a microstrip line printed on a cylindrical substrate composed of multiple dielectric layers

Full-Wave and Fast Analysis of Conformal Microstrip Lines and Antennas

This paper describes a technique known as discrete mode matching, which is suitable for the full-wave simulation of conformal microstrip structures. This contribution presents the theory behind this method, along with the analysis of microstrip lines and antennas conformed on cylindrical surfaces. The results have been compared with data obtained using other techniques and good agreement has been verified

Analysis of conformal microstrip antennas with the discrete mode matching method

An extension of the discrete mode matching (DMM) method is used to analyze microstrip antennas conformed to cylinders. The structure needs to be discretized only along the azimuthal and the axial directions by sampling the fields and current densities in the interfaces between dielectric layers. The solution in the radial direction is obtained analytically with the dyadic Green’s function, which is calculated using the full-wave equivalent circuit (FWEC) in the spectral domain. The structure is truncated in the axial direction by employing absorbing boundary conditions (ABCs). The mathematical formulation is given in this paper, followed by its application to compute the main properties of conformal microstrip antennas, such as resonant frequency, radiation patterns and input impedance. Validation with the commercial software HFSS has been done and good agreement between the results has been observed

Microstrip Antennas for Robust Navigation Receivers

For precise satellite navigation, the reception of more than one frequency band of the whole GPS/Galileo spectrum is required. However, interference from different sources like hand-sets, base-stations for mobile communications or military and civil aircraft radars is a permanent threat for the receiver. Consequently, large errors in positioning can arise. This is a serious problem and not acceptable in safety-of-life applications like aircraft landing. To minimize the impact of interferers, suitable steep bandpass filters or multiplexers with low insertion loss can be employed in the front end between the antenna and the LNA. A better way, however, is to avoid the additional expenditure and realize bandpass and stopband functions in the antenna design, which also reduces the noise figure of the whole receiver. This paper presents different broadband and narrowband antenna developments for multifrequency navigation receivers and a new concept to integrate a diplexer function directly in the antenna

On the Discretization for the Discrete Mode Matching Method for Conformal Microstrip Structures

This paper presents the analysis of cylinder-conformal microstrip lines and resonators with the discrete mode matching method. The focus of the analyses is the assessment of the accuracy of the results by using different discretization schemes on the metallizations. From the theoretical results, it becomes clear that the use of a suitable discretization scheme can provide highly accurate results with the use of only very few discretization lines, hence reducing simulation time and needed computer resources. The results are validated by comparison with measured data found in the literature and with numerical data calculated with ANSYS HFSS

Discrete Mode Matching Analysis of Cylindrical Microstrip Structures

This paper presents the formulation to apply the discrete mode matching (DMM) method to analyze microstrip multilayer structures, such as transmission lines and antennas conformed to cylinders. The main advantage of the method is the need of discretization only along the azimuthal and the axial directions by sampling the fields and current densities in the interfaces between dielectric layers. The solution in the radial direction is obtained analytically with the dyadic Green’s function, which is calculated using the full-wave equivalent circuit (FWEC) in the spectral domain. The method is used to analyze a multilayer conformal transmission line and an antenna is shown. Validation with the commercial software HFSS has been done and good agreement between the results has been observed

A Simulation Technique for RF Amplifier Circuits Using ANSYS Electronics Desktop

This paper describes a simulation technique for RF amplifier circuits using an electromagnetic simulator. To validate the proposed approach two RF circuits were designed, manufactured and measured. Simulated and measured results were compared and good agreement was observed

Aviation Applications: Hybrid Navigation Techniques and Safety-of-Life Requirements, Part 1

This paper describes some key results of the UniTaS IV project, a publicly funded effort to investigate special problems in the application of satellite navigation for aviation. Among the subjects covered: adaptive beamforming antennas, a GNSS landing system that incorporates inertial sensors with a ground-based augmentation system (GBAS), multiconstellation RAIM (receiver autonomous integrity monitoring), and jamming, spoofing, and authentication of signals