2.3 agitation. Thermal noise in an RC

2.3 Analyse and discuss the differences of the measured parameter against the calculated values ( 3dB Cut-off and attenuation included in discussion)The difference between both measured parameter and calculated was significant. The values used from the start for C1, C3 and C5 were 8nF, 24nF and 8nF respectively but results were displaying astonishing results of having cut off points was almost half than needed(136MHZ). Furthermore, the response that was given was not the traditional Butterworth RF filter, it was instead a type II Chebyshev response as shown below:This shows how sensitive the filter was due to the components and also how much noise the components were contributing to the failed response, this was then solved by using smaller valued capacitor and was further improved by cutting the access “legs” of the capacitors. This can be further proved by judging the pattern of the middle capacitor, “C3”, with the biggest capacitance, affects the filter response the most while the side capacitors, “C1” and “C2” barely affected the response after changing the values. Furthermore, after cutting off the access “legs”, a smoother response was displayed.The value of 7nF, 8nF and 7nF for C1, C2 and C3 respectively, ultimately gave the closest cut off point of 250MHz. component noises. Resistors will not always be consistent due to voltage coefficient (Vc) & power coefficient (Pc). Depending on the method of production, resistors that are produced by distinct techniques, such as thin film or metal resistors are necessary in a high performance signal chain. The input capacitors may also add significant distortion if not specified correctly. Polystyrene and some ceramic capacitors can be good alternatives to improve the total harmonic distortion.Besides amplifier noise, resistors and capacitors have electronic noise that is generated by the thermal agitation. Thermal noise in an RC circuit is very simple, as higher resistance contributes to more noise.Two formulas are given to estimate the rms thermal component noise:kB = Boltzmann constantT is temperature +273f is the approximated bandwidth The was no problem getting the desired attenuation from the start.2.4 Highlight the critical aspects of testing and measurement consideration.During testing and measurement for the RF filter frequency response, there are many conditions to take note.Firstly, setting parameters. Whenever a frequency response is being displayed on the spectrum analyzer, there will be several variables to set. 1. The frequency span, 2. Middle frequency and 3. The amplitude.Secondly, as mentioned in the discussion above, there are many ways that components can affect the filter responseLastly, factors that affect the roll-off rate and flatness of the in-band signal. The main solution for it is to increase filter stages/orders which helps to improve the flatness of the in-band signal and improve the steepness of the signal. however , the only drawback of this way is with more added components/ higher orders, the filter will become more sensitive to calculate as many factors mentioned above will affect the actual measured gain.