Physical Essay Paper on History of Microwave Development

History of Microwave Development

       A microwave is an electromagnetic radiation with a wave length of 1mm to 30cm. It is an appliance used in the kitchen to heat food. The history of a microwave oven dates back to 1946 during the Second World War. It came about as a result of a vacuum containing tube called magnetron that could produce microwave radiations. It was first discovered at radar technology by Dr Percy Le Baron Spencer who was working with a candy bar in his pocket and later realized that the radiations of microwave had melted the candy. He then found out after several experiments that microwaves could quickly cook food. In 1954, Raytheon Corporation decided to make the first microwave oven, which was big and expensive. It contained like 1600 watts of power and it was named Radarange 1161.This was a commercial type but a domestic one was first made by Amana in 1967. Microwaves are good in warming already cooked food because they heat up food unevenly hence not recommended for uncooked food (Smith 2013). Microwaves were important during the war period in making radar because that could locate planes and ships belonging to enemies. Radar was used to locate smaller targets as well.

     Microwaves work by producing microwave radiations that come into contact with food. The food contains water and other substances like fats that are able to absorb energy produced by microwaves. Water molecules are charged positively on one side and negatively on the other side. Microwave radiation when applied causes these molecules to have a lot of energy than before. The waves have both magnetic and electrical fields that interchange at a speed of two point four five billion times per second. Water in the food will definitely move along with the electric field of the radiation (Smith 2013). The interchanging field bombards the water

molecules backward to forward and friction between the molecules in this commotion generates heat as the motion causes disruption in the hydrogen bonds between molecules of the water. The heat generated is as a result of both potential and kinetic energy.

      Microwave design comprises of analog circuits in hundreds of megahertz (MHZ) to gigahertz (GHZ) range. Analog signals in microwaves can operate at any current and voltage level at a given time like in their minimum and maximum. Analog signals that are standard are usually between direct current and very few megahertz. The signals of a microwave are either one frequency or many frequencies put on a high carrier of frequency (Lill 2009). The circuits of a microwave are made such that they can take in signals of required band and leave energy that is out of the desired range. The band of signals can be either wide or narrow in size. Narrow circuit bands usually pass bands of less than one megahertz while broader circuit bands pass up to 10 megahertz. When microwaves exist in the same space as digital, the circuit bands of the microwave fall due to the nature of its design out of the range in which digital signals exist. The design of the microwave PC is in accordance with physics laws. Signals of microwave being sensitive, they have to be handled with care. Microwaves too need to have a line for transmitting energy from one point to another. The wires are of certain controlled sizes and operate in a dielectric that is controlled as well in order to produce impedance that is controlled. Loop functioning of signals and the path of return determines inductance while signal spacing to return path causes capacitance (Manning, 2009). This is for example where small spacing causes high capacitance and low impedance. When low impedance does not provide the path of return for microwave signals, they tend to look for their own alternative way.

       The design process had associated problems one of which is a lot of research involved that is tiresome and time wasting. A lot of time is also used when modeling important parts. Design challenges are in micro strip antennas, microwave filters, a micro strip-via and also some high power, critical components like RF-window and tapers. This then means employment of designs that are different for these applications. The choice of type of package, the way components are placed and other structures during assembly will help in determination of the performance of the system in general. Other problems with the design include the weight, and occupation of a lot of space. Frequencies of microwaves also present problems like generation and transmission. Increase in counts of substrate layer, complex technologies of packaging, and closer proximities in design make the microwave design challenging. Integrated circuit that are seamless and tools of EM simulation that move from entry to verification and production have as well caused challenges to the design of microwaves. New innovations in technology in quest to improve accuracy have caused speed reduction (Manning, 2009).

      There are different ideas on microwave design especially with an aim of saving space as well as making it look uniquely special. This consists of microwaves built in with a trim kit or in cabinets and on counter tops as well as below cooking areas. Much exposure to the rays produced by microwaves can cause harm to one’s health. Diseases like cataracts can emanate from too much exposure as well as burns. These can be from leakages of radiations hence it is crucial that one knows how to test for these leakages. They do not need special gadgets or skills to check. An example is unplugging from the socket and not switching off .Check for leakages and returns the plug into the socket.

      Using the microwave involves a few steps like placing food that is to be cooked into the microwave after plugging into the socket. After that, set the time by either turning the knob clockwise to the time required or if it has tabs, just type the required minutes and press cook or start. The microwave will automatically stop once the set time is over. It is not advisable to cook food with little water for more than a minute using a microwave (Manning, 2009). Microwaves are known to cook food throughout at a go as opposed to cooking inside out. Avoid overloading microwaves in order to prevent them from wearing out. The invention of microwaves and their design has played a major role in transformation. Many households can now afford purchasing and enjoying faster cooking of their food due to many players who have since come in the manufacturing industries. This is due to high supply in the market as opposed to initial times when few manufacturers were available and took advantage of raising prices.

References

Lill, J, (2009). Microwave Assisted Proteomics. Royal Society of Chemistry. UK. Web. 25 Oct 2014. http://books.google.co.ke/books?id=41hAT2R_1hcC&pg=PA21&lpg=PA21&dq=Microwave+Assisted+Proteomics&source=bl&ots=b1wLC3v9DU&sig=wMYxHgmljb7edYuoAsHXWKpjyhk&hl=en&sa=X&ei=9QlMVM7aFYzeaNe5gGg&redir_esc=y#v=onepage&q&f=false

Manning, T. Microwave Radio Transmission Design Guide. Artech House: Norwood. Web. 25 Oct 2014. http://books.google.co.ke/books?id=15wiVQwLMNwC&printsec=frontcover#v=onepage&q&f=false

Smith, A. (2013). Eating History: Thirty Turning Points in the Making of American Cuisine. Columbia University Press. USA. Web. 25 Oct 2014. http://books.google.co.ke/books?id=1514y0UnSdQC&printsec=frontcover#v=onepage&q&f=false