RF and Microwave Technology: Applications and History
RF and Microwave Technology: Applications and History
The Rise of Wireless Telephony
“Anywhere, at any time.” Modern wireless telephony is based on the concept of cellular frequency reuse, a technique first proposed by Bell Labs in 1947 but not practically implemented until the 1970s. By this time, advances in miniaturization, as well as increasing demand for wireless communications, drove the introduction of several early cellular telephone systems in Europe, the United States, and Japan.
- The Nordic
Active Filters: Types and Applications in Electronics
Active Filters
As you know, the characteristic that determines an electrical signal is frequency. In many practical cases, a circuit may carry more than one electrical signal, i.e., electrical signals with different frequencies can pass through. However, there may be circumstances where only one of these signals is of interest. This “selection” of an electrical signal by frequency is what filters do.
Initially, filters were composed solely of passive elements, i.e., resistors, capacitors, and inductors.
Read MoreVon Neumann Architecture and Computer Fundamentals
Von Neumann Architecture
It is standard to store data in memory and execute it in a processor. From there, all computers work this way.
- CPU
- Control Unit (CU): It is in charge of interpreting instructions and managing the machine, generating the necessary signals for operations control.
- Instruction Decoder (ID)
- Clock: Marks the time.
- Selector: Marks the order of instructions and synchronizes with the clock.
- Arithmetic Logic Unit (ALU): Its function is to operate the data that it receives preferentially
Stable Feedback and State Estimation Techniques
Stable Feedback: General Case
State: x = Ax + Bu, | x Î Rn, u Î R | |||||||||||
Control: u = –Kx with K =[K1 | K2 | Kn ]1´n | ||||||||||
D | ||||||||||||
+ | ||||||||||||
r | u | + | ̇ | + | y | |||||||
+ | B | ʃ | C | |||||||||
+ | ||||||||||||
Ax | ||||||||||||||||||||
A | ||||||||||||||||||||
K | ||||||||||||||||||||
ì | Figure 14-1. Closed-loop system state diagram. | |||||||||||||||||||
D | ||||||||||||||||||||
ïx | = ( A – BK )x = Afx | , | ||||||||||||||||||
\í | ||||||||||||||||||||
ïA | f | = A – BK ¬closed – loop matrix | ||||||||||||||||||
î | ||||||||||||||||||||
the characteristic polynomial for the closed-loop system is | ||||||||||||||||||||
det(sI – Af ) = det(sI – A + BK ) = 0 | ||||||||||||||||||||
Let the Design Specification require closed-loop eigenvalues at | –l1,-l2 , ,-ln . | |||||||||||||||||||
\a | c | (s) = (s +l )(s +l | 2 | ) (s +l | n | ) = s n+a | n-1 | s n–1+ +a | s +a | 0 | = 0 | |||||||||
1 | 1 | |||||||||||||||||||
Pole-placement design
Read MoreInduction Motor Formulas: Power, Speed, and Efficiency
Induction Motor Formulas
COSy = R2/R1+SN / %((R1+R2/SN)^2+(X1+X2)^2)
Apparent Power
SN = (%3) * V1L * I1L
Reactive Power
QN = SN * SENy
Active Power
PN = SN * COSy
Motor Input Power
3 * (R2/S) * IF2
If Connected in Delta
IN,F = VF / %((R1 + R2/S)2 + (X1 X2 )2)
IN,F = IN,L = (%3) * IN,F
If Connected in Star
IN,F = VF/(%3) / %((R1 + R2/S)2 + ( X1 + X2 )2)
Efficiency
REND = P2 / (P2 + Pcu,1 + Pcu,2 + PFe + Pm) * 100
Pcu,1 = 3 * R1 * I1F2
Pcu,2 = 3 * R2 * I1F2
PFe = 3 * RFe * I1F2
P1 = (%) * V1,L * I1L * COSy
P2 = PN =
Microcontroller Timers and Pin Configuration
Time Counters
Mode 0: The counter register is configured as 13-bit. When the maximum value transition occurs (THx.7 THx.6 … THx.1 THx.0 TLx.4 TLx.3 … TLx.0) = 1111111111111 to zero, the Interrupt flag is activated (TF0, for x = 0 or TF1, for x = 1). It is similar to Mode 1; however, in this case, the 16 bits of the counter register are used (pair TH/TL, THx.0 TLx.7 with THx.7 … … TLx.0); that is, the Interrupt flag is activated when the transition from FFFFh to 0000h occurs in TH/TL. In a
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