3.1 Overview
As described in chapter 2 (Theoretical Background), COPLAN for ADS is a numerical simulation tool which is implemented as a library of Coplanar Elements into the environment of ADS. All elements are calculated as real 3D-elements using field-theoretical calculations and the numerical results are used for the extraction of an equivalent circuit. Since the numerical computations take place at the background, the user does not need to take care of anything regarding the field calculations and can handle the library quite similar to other libraries (like Microstrip Elements) within ADS. The implementation of COPLAN for ADS in ADS is shown in Figure 3-1.
Figure 3-1. Implementation of COPLAN for ADS
After the installation of COPLAN for ADS, the user can design the circuit within schematic window and default window of ADS using the coplanar data items and elements which are available in the library palette. A test-bench can be defined in the test window of ADS and the analysis can be started. During a frequency independent pre-analysis the equivalent circuit parameters for each element are calculated by the FDM-solution of Laplace´s Equation (see chapter 2, Theoretical Background). The number of iterations, the residual error and the name of the model are displayed inside the ADS Status Window. Input parameters and the results (equivalent circuit parameters) are stored by the cache management in a data base file. During simulator startup this file is loaded into memory and works then like a cache. Based on these results a frequency dependent analysis is started and the S-parameters are calculated.
The COPLAN for ADS consists of two palettes of coplanar elements and a palette of special data items. Each element represents a specific coplanar structure like tee-junction, bend, spiral inductor etc. Special data items are introduced in order to reduce the number of input parameters for each model. These data items have a similar function as the well known data items like MSUB item of the microstrip library or the general UNIT item. The list of implemented data items and coplanar elements as well as their use will be described in the next pages.