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utorak

rujan

2011

MICROWAVE AND RADIO FREQUENCY - MICROWAVE AND


MICROWAVE AND RADIO FREQUENCY - LG MICROWAVE TOASTER OVEN - COUNTERTOP MICROWAVE CONVECTION OVENS



Microwave And Radio Frequency





microwave and radio frequency






    radio frequency
  • an electromagnetic wave frequency between audio and infrared

  • A frequency or band of frequencies in the range 104 to 1011 or 1012 Hz, suitable for use in telecommunications

  • Radio frequency (RF) is a rate of oscillation in the range of about 30 kHz to 300 GHz, which corresponds to the frequency of electrical signals normally used to produce and detect radio waves.

  • (Radio frequencies (RF)) Periodic electrical signals transmitted through air or space.





    microwave
  • An electromagnetic wave with a wavelength in the range 0.001–0.3 m, shorter than that of a normal radio wave but longer than those of infrared radiation. Microwaves are used in radar, in communications, and for heating in microwave ovens and in various industrial processes

  • a short electromagnetic wave (longer than infrared but shorter than radio waves); used for radar and microwave ovens and for transmitting telephone, facsimile, video and data

  • cook or heat in a microwave oven; "You can microwave the leftovers"

  • kitchen appliance that cooks food by passing an electromagnetic wave through it; heat results from the absorption of energy by the water molecules in the food











microwave and radio frequency - Radio-Frequency and




Radio-Frequency and Microwave Communication Circuits: Analysis and Design


Radio-Frequency and Microwave Communication Circuits: Analysis and Design



The products that drive the wireless communication industry, such as cell phones and pagers, employ circuits that operate at radio and microwave frequencies. Following on from a highly successful first edition, the second edition provides readers with a detailed introduction to RF and microwave circuits. Throughout, examples from real-world devices and engineering problems are used to great effect to illustrate circuit concepts.
* Takes a top-down approach, describing circuits in the overall context of communication systems.
* Presents expanded coverage of waveguides and FT mixers.
* Discusses new areas such as oscillators design and digital communication.
*An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.










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Overwhelming requests for radiation survey meters




Overwhelming requests for radiation survey meters





Thank you for taking an interest in SE International's radiation detection instrumentation.

Since 1979 RADIATION ALERT® instruments have proven ideal for a wide range of applications.

As the manufacturer of our products, we have engineered them to be reliable, simple to use and understand, and affordably priced.

We're dedicated to our customers and promise to help you find the appropriate instrument for your needs.

Emergency Response and Preparedness

Since the event of September 11, we have had an increased amount of calls from individuals wanting to be informed if a radiation event takes place. Radiation is a scary topic for most individuals, but some basic knowledge will help in determining what action to take when exposed to radiation in an emergency response situation.

The types of radiation encountered during such an event are alpha, beta, and gamma. Alpha and beta are particles and gamma is a ray/photon.

A piece of paper can stop alpha and a few millimeters of aluminum foil can stop most betas.

We say most beta energies because there are high energy betas that are more penatrable.

Most people consider alpha and beta not to be of a concern; however, these particles can be ingested or inhaled and cause damage to the body.

There are high and low levels of gamma, but the primary concern with gamma radiation is the amount of time you are exposed to it.

There are two types of monitoring devices that are applicable in an emergency response to radiation.

One is a rate meter/general purpose Geiger counter.

This type of instrument shows the rate that the radiation is being received.

The other is a dosimeter. A dosimeter shows the amount/dose being received.

When measuring radiation in an emergency response situation, it is good to have something to compare your readings to.

Taking a background radiations level in your area before a radiation event, will help you determine if you have a radiation elevation and whether or not to stay in that location.

Background radiation is naturally occurring radiation that is always present.

It includes; high energy gamma rays from the sun and outer space and alpha, beta, gamma radiation emitted from elements in the earth. Using a rate meter, you can determine what your normal background is.

It is up to the individual to decide what a safe radiation level is because it differs depending on the individual and their knowledge of radiation and its affects.

As an example; say your background level is 25 CPM (counts per minute) where you live.

When you fly in an air plane at 30,000 feet your rate meter is getting 200 CPM for anywhere between 2 to 5 hours.

That is 8 times what your normal background is on the ground, but it is for a limited amount of time.

There are non-occupational dose limits set by the government which is 100 mR per year above background per year.

What we sest for a good emergency response kit for radiation is a general purpose Geiger counter like the Monitor 4, a carbon fiber dosimeter such as the PEN200 and a Charger to reset the dosimeter. T

here are electronic dosimeters, however, if you are in the blast zone of a nuclear bomb the pulse of the bombs render most electronic inoperable but the carbon style dosimeters will still operate.



A Brief Overview of Radiation Detection

None of the instruments listed in this website detect neutron, microwave, RF (radio frequency), laser, infrared, or ultraviolet radiation.

All of the instruments are most accurate for Cesium 137 and isotopes of similar energies.

Some isotopes detected relatively well are Cobalt 60, Technicium 99M, Phosphorous 32, Strontium 90, and many forms of Radium, Plutonium, Uranium, and Thorium.

Some forms of radiation are very difficult or impossible for a Geiger tube to detect.

Tritium is a byproduct of a nuclear reactor and is used in research.

The beta emissions from Tritium are so weak that there are very few instruments that are capable of detecting it.

More sophisticated equipment is needed for the measurement of environmental samples, such as radioactivity in milk, produce, soil, etc., unless you are looking for gross contamination.

The radiation from some isotopes can cause a Geiger tube to overexcite and indicate a higher level of radiation than is actually present.

Americium 241 is an example of this phenomenon.

Americium 241 is used in some smoke detectors and many different types of industrial density and flow meters.

Unless you know exactly what you are measuring and understand the limitations of detection instruments, it is possible to draw misleading conclusions from your readings.

We design our instruments to detect the broadest range of ionizing radiation possible and still be affordable.

The full spectrum of ionizing radiation cannot be measured by one single instrument.

Everyone agrees that radioactive materials can be dangerous. We encourage you to seek out other sources of information.















Swiss Weather Anomaly - animation




Swiss Weather Anomaly - animation





Click 'ALL SIZES" to view animation!

On the morning of the 24th of April 2009 employees at MeteoSwiss (Switzerland's Federal Office of Meteorology and Climatology) got the surprise of their lives. Huge circular fields hovering over Switzerland were picked up by their radars. The question was asked as to whether a massive UFO was in the upper-atmosphere above the scenic mountainous nation or perhaps these circles were signs of an imminent hurricane or maybe some sort of electromagnetic radio frequency/microwave technology is in use to cause such an anomaly.

Felix Schacher, a senior Meteorologist at MeteoSwiss claimed the circles were not UFOs or the signs of a hurricane about to wreak havoc on his country. Mr Schacher told the Swiss news site '20 Minutes' that they were merely caused by the reflection of water droplets that just happened to form a circular shape.

A few minutes after being queried on the issue the radar images were hurriedly removed from the departments website. Many Swiss UFO researchers have left comments on various internet forums expressing their doubt on the 'reflection water droplets' story, asking why was the image so quickly removed and who ordered its removal.

Many people also left some comments on forums asking if the interference patterns shown on the meteorological map, could be caused by trials in relation to the startup of the LHC - Large Hadron Collider near Geneve also, in Switzerland.

Please, feel free to comment!!










microwave and radio frequency








microwave and radio frequency




Radio Frequency and Microwave Electronics Illustrated






For undergraduate course in RF electronics and Microwave Circuits and Devices. This highly illustrated resource makes grasping the fundamentals of RF and microwave electronic theory and design easier and faster. Begins at the rudimentary level of axioms and postulates of physical sciences and progresses to introduce low-frequency transistor circuit analysis and design, RF electronics and wave fundamentals, microstrip lines, and the application of the Smith chart in lumped and distributed circuit analysis and design.










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