Bolometer systems would be simplified considerably if all components could be made photolithographically on a single substrate. We are developing a design for a single-substrate array with several frequency bands that incorporates a planar antenna for coupling to the telescope, transmission-line filters for separating and defining frequency bands,
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and lithographed bolometers. Antenna Coupling: Bolometer arrays are usually coupled to telescopes either by horns or by placing the absorbers directly in the focal plane. Another possible method is to use planar antennas. Planar antennas control the solid angle that is visible to the bolometer as with a horn, but are much easier to fabricate in large arrays. Our current design uses a double-slot dipole [filipovic97]. This antenna has many good features for use in bolometer arrays. It has a symmetric beam pattern and an impedance suitable for matching to microstrip transmission line. A dielectric lens in direct contact with the antenna is typically used, and the combination antenna/lens can be matched to the f/# of a telescope by adjusting the parameters of the lens. A dual polarization version of the double-slot dipole has been developed by Chattopadhyay and Zmuidzinas [chattopadhyay98]. Transmission-line Filters and RF Multiplexers: A planar antenna couples radiation from the telescope to a transmission line, for example, microstrip. Transmission-line elements can be used to separate the RF energy into multiple well defined frequency bands. There is a considerable literature on such devices from the electrical engineering community. We are investigating superconducting Nb microstrip resonant stub filters. The stubs are lambda in length and can be modeled as ``LC`` resonators. The in-band transmission of such filters can...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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