Abstract: A termination fixture for exciting an electrodeless lamp with high frequency power matches a capacitive complex impedance of the lamp in an excited state to the output impedance of the high frequency source coupled to the fixture. The fixture has a pair of coaxial conductors which have a length of one quarter wavelength and which have a ratio of diameters effective to match the real impedance of the lamp to the impedance of the source. A helical coil couples the end of the inner conductor to the lamp. The purpose of the coil is to make the impedance of the lamp, as viewed, electrically, from the end of the inner conductor appear as having only the real component. The quarter wave fixture then matches the real impedance to the source impedance.

Abstract: An improved termination fixture for an electrodeless light source matches the complex impedance of an electrodeless lamp during excitation to the output impedance of a high frequency power source coupled to the fixture. The inner conductor of the fixture has a first and a second section. The dimensions of the first section are such as to produce an input impedance whose reactive impedance part is much smaller than the reactive impedance part of the lamp impedance. The dimensions of the second section are such as to match the input impedance to the source output impedance.

Abstract: An electrodeless lamp is positioned at the end of an inner and outer conductor forming a termination fixture, the inner conductor being shaped such that the arc within the lamp during excitation is isolated from the wall of the lamp envelope. The inner conductor may be formed as a hollow helical element thereby providing both an axial and azimuthal electric field component. Alternatively, the inner conductor may be cup-shaped which has a shielding effect to control the electric field strength at the end of the conductor. The helical or cup element and other features of the inner conductor provide both arc shaping and impedance matching between the complex impedance of the lamp during operation and the output impedance of a high frequency power source which is coupled to the termination fixture.

Abstract: An electrodeless lamp is excited in a termination fixture by high frequency power, the lamp being located within the fixture at the end of an inner conductor whose end is shaped such as to inhibit the arc of the lamp from attaching to the lamp envelope. In one embodiment, the inner conductor end is shaped as a hollow helical coil which generates an axial and azimuthal electric field component to create a torodial arc within the lamp. In another embodiment the inner conductor end is cup-shaped to provide a field shielding effect which distributes the field strength more uniformly across the end of the inner conductor.