Character L circuit The impedance distribution circuit L has 4 forms as shown below: Figure 1.1: 4 types of impedance matching circuits L In which, there are two cases to consider: <
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Hanoi University of Science and Technology
School of Electrical and Electronics Engineering
REPORT
ANALOG CIRCUIT DESIGN II
Student: Do Nhat Hoang 20193219
Class: Advanced of Electronic Engineering K64 Instructor: Dr Nguyen Nam Phong
Hanoi, 03/2022
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Table of Contents
PART 1 CHARACTER L, PI AND T CIRCUITS DESIGN 3
1.1 Character L circuit 3
1.1.1: ( C ) Circuit 4
1.1.2 ( B) Circuit 5
1.1.3 ( D) Circuit 5
1.2 Pi Circuit 6
1.2.1 Low-pass Pi circuit: 7
1.2.1: High-pass Pi circuit: 8
1.3 Circuit of the letter T: 9
1.3.1 Low-pass T-circuit: 10
1.3.1 High-pass T-circuit: 11
PART 2 COMPARISON AND VALIDATION 12
2.1 Circuit classification 12
2.2 Advantage and disadvantage of each circuit 12
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3
PART 1 CHARACTER L, PI AND T CIRCUITS DESIGN
1.1 Character L circuit
The impedance distribution circuit L has 4 forms as shown below:
Figure 1.1: 4 types of impedance matching circuits L
In which, there are two cases to consider: < 𝑅𝐿 and > 𝑅𝐿 Down here is the circuit structure for the two cases, with is the series reactance, is parallel reactance:
Figure 1.2: Circuit structure with RS < RL
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Figure 1.3: Circuit structure with RS > RL
1.1.1: ( C ) Circuit
Consider a high-pass L circuit with RS < RL:
Figure 1.4: High-pass L circuit with RS < RL
Consider the circuit with series reactance C and parallel reactance L:
That
So that we have:
Also have:
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1.1.2 ( B) Circuit
Consider a low-pass L circuit with RS > RL:
Figure 1.5: Low-pass L circuit with RS > RL
Consider a circuit with series reactance L and parallel reactance C:
We have:
Performing the same transformation as circuit C, we get:
1.1.3 ( D) Circuit
Consider high-pass L circuit with RS > RL:
Figure 1.6: High-pass L circuit with RS > RL
We have:
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Similar to the case of circuit B, we have:
1.2 Pi Circuit
Figure 2.1: General Pi circuit
The Pi circuit can be described as two "opposed" L circuits, both of which are configurable to match the load and source with an invisible or “virtual” resistor located at the junction between the two networks
Figure 2.2: Pi circuit is equivalent to two opposing L circuits, with phantom
resistance in between
Q value of Pi circuit:
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From the result of circuit L, we have:
We also have:
From this we can determine the corresponding reactance values Pi circuits can be divided into two basic types: low-pass circuits and circuits high pass
1.2.1 Low-pass Pi circuit:
Figure 2.3: Low-pass Pi circuit
We have:
We also have:
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From that we can calculate the value of 𝑋𝐿, 𝑋𝐶1, 𝑋𝐶2
With : 𝑋𝐿 = 𝑋𝐿1 + 𝑋𝐿2
1.2.1: High-pass Pi circuit:
Figure 2.4: High-pass Pi circuit
We have:
We also have:
From that we can calculate the value of 𝑋C, 𝑋L1, 𝑋L2
With : 𝑋C = 𝑋C 1 + 𝑋C 2
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1.3 Circuit of the letter T:
Figure 3.2: General T circuit
Circuit T can be described as two series L circuits used to connect the load and source with a virtual resistor RV placed at the junction between two networks L RV must
be chosen greater than both and since it is connected connected to the shunt pin of each part of the L circuit
Figure 3.2: The T-circuit is the form of two L-circuits in series
The Q value of T circuit:
From the result of circuit L, we have:
We also have:
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From this we can determine the corresponding reactance values
T-circuits can be divided into two basic types: low-pass circuits and high-pass circuits
1.3.1 Low-pass T-circuit:
Figure 3.3: Low-pass T-circuit
We have:
We also have:
From that we can calculate the value of 𝑋C, 𝑋L1, 𝑋L2
With : 𝑋C = 𝑋C 1 // 𝑋C 2
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1.3.1 High-pass T-circuit:
Figure 3.4: High-pass T-circuit
We have:
We also have:
From that we can calculate the value of 𝑋L, 𝑋C1, 𝑋C2
With : 𝑋L = 𝑋L 1 // 𝑋L 2
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2.1 Circuit classification
Does not need to control
bandwidth
Need to control bandwidth
Q value gains from
calculation with given
reactance
Can choose the Q value Virtual resistance in
circuit Pi must be smaller resistance on the source and load
Virtual resistance in circuit T must be larger resistance on the source and load
2.2 Advantage and disadvantage of each circuit
in low pass filter
The circuit can change to L circuit by setting
a capacitor equal
to 0 Therefore it
is very flexible
- Good at high pass filter
- May be used for multi-band with the suitable value of L and C
bandwidth
- Hard to create
capacitor and inductor to work
at microwave frequency
- Require complex algorithm to design automatic impedance matching
- High cost due to having more components than L circuit
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References [1] Behzad Razavi (2011) RF Microelectronics, 2nd Edition, Pearson [2] Metin Şengül, Gökmen Yeşilyurt (2017) “Real frequency design of Pi and T matching networks with complex terminations”, 2017 10th International Conference on Electrical and Electronics Engineering (ELECO)
[3]A.R., A K., Singh, S G., & Dutta, A (2018) “Analytical design technique for real- -real single- and dual-frequency impedance to matching networks in lossy passive environment”, IET Microwaves, Antennas & Propagation, 12(6), 1013–1020
doi:10.1049/ietmap.2017.078