I hope you pass your exam! I wish I can make more videos here but pandemic pushed our institution to make a KZfaq channel. All my videos will be uploaded there now.

@@charlestondaleambatali4158 oh okay ! Thank you sir, I wish too. Can you please give me the name of the youtube channel ?

@@khaben6986 apologies for the very late reply. If it is still relevant to you, here is the channel. :) kzfaq.info/love/PdaaAjjeJaXyPLlE_kUVaA

Glad to be of service. :)

Hello. T and Pi network can only push you to higher Q values. If you want low Q values, you need to use cascaded L networks. They look like cascaded Pi/T networks but it is more appropriate to think that they are cascaded L networks and between each network, you are matching the current load to some virtual resistance. With the correct values of virtual resistances, you will obtain a wideband match.

Carlos Eduardo Mayer de Oliveira you are welcome!

Rounding error. It is acceptable. In practical implementation, you will have a large tolerance from your electronic components, anyway.

Stub matching networks are not covered by this video. The two stubs are mainly used when there is no space in your circuit board for long stub matching networks. The position of the stubs can be varied along the lines but affixing them near the load end and source end ensures the smallest area needed.

Rvirtual is a value of a resistance you need to achieve a specific Q-factor. Since we are designing the network to have a higher Q-factor, 2 elements are not enough. You need three elements to achieve a higher Q-factor. The middle element can be split into two. In the case of a shunt element, it will become two parallel shunt elements. For a series element, it will be two series elements. In between the split lies a virtual resistance that you will need to compute based on the Q-factor you need. Once you get the virtual resistance, you can compute for the values of the split elements and combine them into one (parallel combination for the shunt, series combination for the series).

I already updated the descriptions. Thank you for waiting.

Hello. By increasing the number of elements, you decrease the Q-factor of the circuit. In a chain of L-matching networks, the largest Q-factor of one L-network is approximately the Q-factor of the whole circuit. Successive L-networks can be used to maintain a small Q-factor. Look at the slide where the formula for the Q-factor is and try to calculate and simulate it by yourself.

Hello,, Can i ask you any relationship we need to explain how the quality factor will be decreased ,I'm an Arabia student and my English very week.

Kareem Daraghma the quality factor (Q) of one L-network is related to the bandwidth (B) and resonant frequency (f0) by the formula f0=BQ. If we let f0 be constant, then decreasing Q means we increase B. Now, the quality factor for one L-network element is dependent on the load resistance (RL) and the source resistance (RS) by the formula Q=sqrt(RL/RS-1) if RL>RS and Q=sqrt(RS/RL-1) if RS>RL. Now, in between two individual L-networks lies a virtual resistance whose value can be flexible such that you can have a desired Q factor that is less than the Q factor using only one L-matching network. For example, consider two L-networks cascaded with each other. The source resistance is 50 ohms and the load resistance is 100 ohms. If we use one L network to match it, then Q=1. Now, if we set a virtual resistance Rv=75 ohms in between the two L-networks, the Q factor of the matching network from RS to Rv is 0.7071 and Q from Rv to RL is 0.5774. The total Q factor of the circuit is approximately the larger Q factor which is 0.7071. This is less than the Q factor of the single matching network only which is 1. You can simulate this using a circuit simulator and observe the effects.

Thank you.

That is the first time I have heard of that. Also, all educational videos I will be making from now on will be uploaded to our Institute's official KZfaq channel. Apologies.

Give me your replay please

@@kareemdaraghma510 use the G-LC matching network

I do apologize for the very late reply. I hope this will still help. The best type of matching network will largely depend on your specifications. Moreover, aside from the networks discussed in this video, there are still a number of matching network techniques that especially work at high frequencies (above 1 GHz). The goal here should be to find the network that satisfies your needed specifications while minimizing the cost of implementation (number of components used). That is the best matching network.

Can be used in any case as long as you want the Q factor to be large.

@@charlestondaleambatali4158 so there is no advantage of T over pi network? Thank you!

It is not. It is supposed taken by our 4th year students.

you're so rude, there are other way of giving advice to people who teaches for free

My apologies, sorry I offended you. @@AlbertRei3424

What you said about the absorption method becomes apparent when you use the Smith Chart for matching circuits. However, the resonance method exists as an alternative if you want to have a bandpass matching network that is not provided by the absorption method. Moreover, there is the issue of bandwidth where one method may have the better bandwidth specification compared to the other.