Abstract: A small loop antenna employs circuits for increasing the power output and bandwidth of such antennas by employing coaxial cable or wide antenna elements on which the coaxial cable may be mounted or use microstrip, both for the purpose of reducing the inductance and resistance of the antenna structure in a fixed ratio so that the reduced terminating resistance increases the level of signal output. This method applies to both receiving and transmitting antennas for cases where the terminating resistance is much larger than the radiation resistance plus the antenna and tuner loss resistances.

Abstract: A heater employs a ferromagnetic or like material heated by a varying magnetic field to heat the ferromagnetic material wherein the ferromagnetic material has a large cross-section comprised of many members of small cross-section insulated from one another and wherein for medical applications each member may be surrounded by a heat conductive electrically conductive coating.

Abstract: A temperature self-regulating heater has a thin first layer of high magnetic permeability, a second layer of electrially conductive non-magnetic material forming a substrate and a heat conductive dielectric disposed between the layers. A varying (preferably r.f.) magnetic field is imposed upon the exposed surface of the first layer and the material to be heated may be placed in contact with an exposed surface of the second layer or may be the dielectric. The heater may be employed with an induction stove wherein the first layer is disposed above the stove's induction coil and the second layer can be the bottom of a cooking utensil.

Abstract: A heater (seed) and system for subjecting body tissue to closely controlled hyperthermia or higher temperatures includes a core of ferromagnetic material having a high resistivity or resistivity of a non-conductor enclosed with a bio-compatible non-magnetic conductive sheath and excited by a coil positioned to establish a magnetic field coupled to the seed. The core is dimensioned so as to reduce demagnetizing effects to acceptable levels. The thickness of the conductive sheath is optimized to maximize heat generation to achieve a heat generating capacity which is considerably greater than that of the bare ferromagnetic material.

Abstract: A single constant voltage power supply concurrently supplies a plurality of independent loads each with an independently selectable constant current load without interaction between the loads (currents) by employing a plurality of parallel connected circuits of electrical lengths equal to (2n-1)90.degree. each connected between the constant voltage source and a different one of said loads.

Abstract: A self regulating heater comprises a non-conductive, magnetic core having a coil wound about it and providing pole pieces extending into contact or very near contact with a surrounding ferromagnetic member which in turn may be surrounded by and in intimate contact with a non-magnetic low resistance member; the magnetic member having an effective Curie temperature at the temperature to be maintained.

Abstract: A temperature control system is disclosed for controlling heating current to a heater having an impedance which varies substantially with temperature. The change in impedance of the heater changes the degree of mismatch between the power transmission system and the heater resulting in a change in the voltage which is reflected back to the power transmission system. The reflected voltage is monitored and its magnitude compared to a reference source and the power to the heater is controlled in response to this comparison.

Abstract: An electron-bombarded semiconductor (EBS) source including plural EBS diodes connected in series at the fundamental radio frequency operating range delivers power to a load. A single voltage supply is provided and radio frequency isolation means is connected between the series connected diodes and said supply to effectively connect the diodes in parallel with respect to said supply voltage and current.