摘要:
A system for scanning an antenna array of the present invention. The system includes a first mechanism for modulating a desired signal on an optical carrier signal. The first mechanism includes a frequency-tunable optical oscillator with a phase shifter for changing an output frequency of the optical oscillator. A second mechanism employs the optical carrier signal to derive signals having predetermined phase relationships. A third mechanism receives the feed signals and radiates corresponding transmit signals in response thereto to the antenna array to steer the array. In more specific embodiment, the desired signal is a Radio Frequency (RF) signal, and the phase shifter is an electrically controlled optical RF phase shifter. The optical carrier signal includes a first optical carrier signal and a second optical carrier signal. The frequency-tunable optical oscillator includes a first tunable optical oscillator for providing the first optical carrier signal and a second tunable optical oscillator for providing the second optical carrier signal. The first and second optical oscillators include first and second optical RF phase shifters, respectively, that include feedback paths having optical and electrical sections.
摘要:
A millimeter wave (MMW) antenna array includes a continuous transverse stub (CTS) radiating aperture comprising a set of spaced continuous transverse stubs, each having a longitudinal extent. A series feed system is coupled to an excitation source for exciting the stubs with MMW electromagnetic energy having a linear phase progression along the longitudinal extent of the stubs to produce an array beam which can be scanned over a beam scan range by changing the excitation frequency.
摘要:
Compositions and methods are disclosed for substantially liquid, gel, suspension, slurry, semisolid and/or colloid storage of biological samples following admixture with the herein disclosed storage composition, permitting substantial recovery of biological activity following storage without refrigeration. In certain embodiments, unfractionated blood or tissue samples may be stored without refrigeration in a form that permits recovery of intact DNA or RNA components following the storage period.
摘要:
Compositions and methods are disclosed for substantially liquid, gel, suspension, slurry, semisolid and/or colloid storage of biological samples following admixture with the herein disclosed storage composition, permitting substantial recovery of biological activity following storage without refrigeration. In certain embodiments, unfractionated blood or tissue samples may be stored without refrigeration for weeks, months or years in a form that permits recovery of intact DNA, RNA or protein components following the storage period.