| 摘要 |
The coil field electrode for a device for medical shortwave therapy consists of a resonant circuit coil (1), which serves the purpose of electromagnetic coupling to the patient, and one or more capacitors (2) which form a resonant circuit in parallel connection to the resonant circuit coil (1). The resonant circuit is run from a generator via a homogeneous line (4), one line pole (4.1) of which is connected to the start of the first coil winding (1.1) and the other line pole (4.2) of which is connected to this winding (1.1), or to one of the next windings, at a point (5) at which the partial impedance of the resonant circuit existing in the event of resonance between said point and the start of the first winding (1.1) is equal to the characteristic impedance of the line (4). The line (4) can be a low-resistance coaxial cable. A phase discriminator (9) connected on the electrode side to the line controls as a function of the phase shift between current and voltage on the line (4) an actuator (6) which controls a tuning capacitor (3) for automatic impedance matching between the line (4) and resonant circuit. <IMAGE>
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