What are the different types of phase detector?
There are two classes of phase detectors: a linear phase detector, in which the transfer function is somewhat linear between the output and the input phase error, as shown in Figure 4.41(A), and a binary phase detector (or bang-bang phase detector), in which only the sign of the phase error is extracted, as shown in …
How does a phase detector work?
A phase detector is a mixer-like circuit that puts out a signal that is proportional to the phase difference between two input signals of the same frequency.
What is the importance of a phase detector?
The phase detector is an essential element of the phase-locked loop (PLL). Detecting phase difference is important in other applications, such as motor control, radar and telecommunication systems, servo mechanisms, and demodulators.
Which of the following logic gate can act as phase detector?
A common application of this phase detector can be found in digital phase-locked loops. An XOR gate provides a small, simple, and low-power solution. The truth table of the XOR gate is shown to the right. When the inputs are out-of-phase, they will be in opposite states, and the output of the XOR gate will go high.
What is an RF phase detector?
RF phase detectors and comparators are circuits or instruments that provide a DC output voltage proportional to the difference in phase between two RF signals. They include local oscillator (LO), radio frequency (RF), and intermediate frequency (IF) components.
What is a zero crossing detector?
A zero-crossing detector or ZCD is one type of voltage comparator, used to detect a sine waveform transition from positive and negative, that coincides when the i/p crosses the zero voltage condition. The applications of the Zero Crossing Detector are phase meter and time marker generator.
What is phase detector gain?
Phase detector: compares the phase at each input and generates an error signal, ve(t), proportional to the phase difference between the two inputs. KD is the gain of the phase detector (V/rad). Any phase difference then shows up as the control voltage to the VCO, a DC or slowly varying AC signal after filtering.
What is a phase sensitive detector?
An electronic device capable of measuring the difference in phase between a periodic signal and a reference signal in the presence of noise. The signal plus noise is multiplied by a reference waveform whose shape and frequency are similar to those of the signal.
What is the output voltage of phase detector?
Explanation: The output voltage of a phase detector is a dc voltage and is often referred to as error voltage. This output is applied to the low pass filter which removes the high frequency noise and produces a dc level.
What is PLL detector?
A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a variable frequency oscillator and a phase detector in a feedback loop.
What is the example of analog phase detector?
A square wave detector is based on a logic circuit producing a signal that is averaged (or integrated) over time. An example is the XOR gate shown in Figure 6.6. 1(b), which compares two digital signals that here have the same frequency but are shifted in phase.
How does a 2× sampling phase detector work?
Figure 4.42 shows an Alexander phase detector, also known as a 2× sampling phase detector. It uses both edges of a Nyquist-rate clock to sample two consecutive data bits and the data edge in between. The early and late information can be generated based on the sampled results.
How is a low pass filter used in a phase detector?
If there is a phase or frequency difference between the two sources, the phase detector produces an output that is used to correct the VCO. The low-pass filter is used to remove unwanted high-frequency components from the phase detector’s output.
What are the limitations of a phase detector?
Operation of the Alexander phase detector. One limitation of this phase detector is that it requires a Nyquist-rate clock with a good duty cycle since it uses both edges of the clock, which translates to higher power consumption and a more stringent requirement of the clock in high data-rate systems.
Why is a phase detector called a baud rate detector?
This type of phase detector is also called a baud-rate phase detector because 2× sampling is no longer required as is the case with the Alexander phase detector, and, therefore, it opens up the possibility of using the half-rate clock for power saving purpose.