VOLTAGE CONTROLLED VARIABLE POWER DIVIDER NASA Case No. GSC-11659 Canada, Great Britain, Address inquiries to: Goddard Space Flight Center Attn: Patent Counsel Mail Code: 204 Greenbelt, MD 20771 [Corresponding to U.S. Patent No. 3,769,610] In the voltage controlled variable power divider of the invention, the total output power equals the input power and both outputs have constant and equal phase. The applied power is split into two channels, each of which contains a variable phase shifter. The channels are combined in a 90-degree hybrid coupler so that the relative amplitude in the hybrid outputs is a function of the phase of the hybrid input signals. The phase shifters are voltage driven in opposition so that constant phase is achieved for all output power division ratios. Masking selected portions of a ribbon and forming an inter-metallic compounds on the unmasked portions by a controlled diffusion reaction produces a twisted filamentary structure. The masking material prohibits the formation of superconductive material on predetermined areas of the substrate. A need exists in laser technology whereby stable mode-locking can be achieved for a pulsed laser system which is simple and which avoids other known disadvantages. The present invention meets these requirements and includes a pair of partially reflecting mirrors forming the laser cavity. The dual mode-locking elements will pass timed pulses without being extinguished. The need frequently arises to augment narrow beamwidth transmitting and/or receiving antennas with a wide beamwidth "acquisition" mode. The present invention is a switchable beam width antenna employing a common main reflecting dish operable in at least two different beamwidth modes. It includes a concave parabolic main reflecting dish with a central circular region and a surrounding coaxial annular region. The central region of the main dish can be excited for wide beamwidth or the entire dish for narrow beamwidth. ELECTROSTATICALLY CONTROLLED HEAT SHUTTER NASA CASE No. NPO-11942 Australia, Canada, France, Address inquiries to: [Corresponding to U.S. Patent No. 3,763, 928] A heat transfer assembly for conducting thermal energy includes a hermetically sealed container enclosing a quantity of inert gas such as nitrogen. Two opposed walls of the container have high thermal conducting characteristics while the connecting walls have low thermal conducting characteristics. Electrodes are positioned adjacent the high thermal conducting walls and biased relative to the conducting walls to a corona potential for creating an ionic gas wind which must contact the conducting walls to be neutralized. The contact of the gas molecules permits the maximum thermal energy transfer between the walls. Baffles can be positioned adjacent the electrodes to regulate gas flow between the high thermal conducting surfaces. |