**Transmission lines** ====================== A *transmission line* is a specialized cable or other structure designed to conduct electromagnetic waves in a contained manner. The term applies when the conductors are long enough that the wave nature of the transmission must be taken into account. .. _transmission_matrix_def: **Transmission matrix** The **transmission matrix** is one of the ways to describe a microwave device. The :math:`ABCD`-parameters of the device act as elements of this matrix. The matrix equation relates the input voltage and input current to the output voltage and output current. .. _scattering_matrix_def: **Scattering matrix** The **scattering matrix** is one of the ways to describe a microwave device. The :math:`S`-parameters of the device act as elements of this matrix. The matrix equation relates the waves reflected from the input and output to the waves incident on the input and output. .. py:currentmodule:: symplyphysics.laws.electricity.circuits.transmission_lines **Contents:** .. toctree:: :maxdepth: 4 laws.electricity.circuits.transmission_lines.coplanar_lines laws.electricity.circuits.transmission_lines.microstrip_lines laws.electricity.circuits.transmission_lines.coefficient_standing_wave_from_reflection_coefficient laws.electricity.circuits.transmission_lines.coefficient_standing_wave_from_voltages laws.electricity.circuits.transmission_lines.hybrid_parameters_matrix laws.electricity.circuits.transmission_lines.impedances_pi_type_circuit_of_transmission_line laws.electricity.circuits.transmission_lines.impedances_t_type_circuit_of_transmission_line laws.electricity.circuits.transmission_lines.input_impedance_from_parameters_transmission_matrix laws.electricity.circuits.transmission_lines.input_impedance_lossless_transmission_line laws.electricity.circuits.transmission_lines.input_impedance_lossy_transmission_line laws.electricity.circuits.transmission_lines.ratio_of_average_power_to_incident_power_from_reflection_coefficient laws.electricity.circuits.transmission_lines.ratio_of_average_power_to_incident_power_from_standing_wave_coefficient laws.electricity.circuits.transmission_lines.reflection_coefficient_from_load_and_transmission_line_impedances laws.electricity.circuits.transmission_lines.scattering_matrix laws.electricity.circuits.transmission_lines.scattering_matrix_to_transmission_matrix laws.electricity.circuits.transmission_lines.total_conductivities_matrix laws.electricity.circuits.transmission_lines.total_resistance_matrix laws.electricity.circuits.transmission_lines.transmission_matrix laws.electricity.circuits.transmission_lines.transmission_matrix_for_a_parallel_load_in_line laws.electricity.circuits.transmission_lines.transmission_matrix_for_a_series_load_in_line laws.electricity.circuits.transmission_lines.transmission_matrix_lossless_transmission_line laws.electricity.circuits.transmission_lines.transmission_matrix_lossy_transmission_line laws.electricity.circuits.transmission_lines.transmission_matrix_of_pi_type_circuit laws.electricity.circuits.transmission_lines.transmission_matrix_of_t_type_circuit laws.electricity.circuits.transmission_lines.wave_resistance_of_microstrip_line_for_effective_width_greater_thickness laws.electricity.circuits.transmission_lines.wave_resistance_of_microstrip_line_for_effective_width_less_thickness