A 94 GHz pulse Doppler solid-state millimeter-wave cloud radar (MMCR), Tianjian-II (TJ-II), has been developed. It reduces the size and cost using a power amplifier (SSPA) single antenna. This paper describes system design, including hardware signal processing components. Pulse compression, segmented pulse, dual repetition frequency (PRF) technologies are employed to overcome limitations impose...

s the operating frequency of semiconductor solidstate devices increases into the millimeterwave region, the size of the devices and their power handling capability are reduced. In order to provide the advantages of a solid-state technology for moderate power levels at millimeter-wave frequencies, solid-state components must be combined. Spatial power combining provides enhanced RF efficiency by...

A novel attitude measuring sensor is presented to be used on agile satellites without any angular field of view restrictions. The sensor is based on low-cost, medium resolution attitude vector measurements, obtained from geomagnetic detectors (magnetometers) and coarse sun sensors (solar cells). The vector measurements chosen, have an unrestricted field of view and a reasonably high response ba...

Without SM4, gyroscope survival is a critical factor for the HST Mission lifetime. I present a simple Monte-Carlo model to calculate the survival probabilities for various scenarios. I calibrate the model to reproduce and update more accurate, but somewhat outdated, calculations by Aerospace Corporation. Continued three-gyroscope guiding will become impossible by late January 2006. Subsequent t...

We present the first experimental demonstration of the optical Sagnac effect at the single-photon level. Using a high quality guided-wave heralded singlephoton source at 1550 nm and a fibre optics setup, we obtain an interference pattern with net visibilities up to (99.2 ± 0.4%). On the basis of this high visibility and the compactness of the setup, the interest of such a system for fibre optic...

This paper reports a novel four degree-of-freedom (DOF) MEMS vibratory gyroscope. A MEMS gyroscope array is then presented using the novel gyroscope unit. In the design of the proposed 4-DOF MEMS vibratory gyroscope, the elements of the drive-mode are set inside the whole gyroscope architecture, and the elements of sense-mode are set around the drive-mode, which thus makes it possible to combin...

The Kronig–Penney model serves to illustrate the formation of energy bands in a periodic solid and appears as a pedagogical example in many textbooks in elementary solid state physics. The model is generally solved either by matching the boundary conditions for the wave functions at the cell boundaries, by a plane-wave expansion of the wave function in the reciprocal lattice space, or even by t...