MARTHA is a set of general-purpose programs for analyzing linear electrical networks, available to users with access to APL time-sharing systems.
MARTHA is a set of general-purpose programs for analyzing linear electrical networks, available to users with access to APL time-sharing systems. The programs analyze, as a function of frequency, most linear "transmission-type" networks, with an input and an output. This includes most filters, amplifiers, microwave networks, and feedback systems, even if such circuits are relatively complicated, with multiple feedback paths and branches. The programs cannot handle some complicated interconnections of components, and are not set up to analyze nonlinear or time varying networks.
The topology of the network is described using "wiring operators." The elements available include lumped and distributed, active and passive, reciprocal and nonreciprocal elements. The possible output includes tow-port parameters (impedance, admittance, hybrid, scattering, and ABCD matrices), as well as voltage gain, insertion gain, transducer gain, etc. These, their real or imaginary parts, or magnitude or phase, may be printed or plotted as functions of frequency or of each other. More than one network can be analyzed simultaneously.
MARTHA is not inherently better at one frequency range than another, except perhaps in its repertoire of elements and response functions. MARTHA includes, besides R, L, and C, sixteen controlled sources; operational amplifiers; mutual inductance; three transistor models and the possibility of easily creating others; ideal transformers; several composite pi and tee structures; and a few exotic elements such as gyrators. For high-frequency applications MARTHA has several microwave elements, including TEM transmission lines, waveguides, attenuators, and isolators.
