What is a zero IF receiver?
A direct-conversion receiver (DCR), also known as homodyne, synchrodyne, or zero-IF receiver, is a radio receiver design that demodulates the incoming radio signal using synchronous detection driven by a local oscillator whose frequency is identical to, or very close to the carrier frequency of the intended signal.
What is LO leakage?
LO leakage is specified as the ratio of the power of the leaked LO signal to the power of the desired output signal. In an ideal double-balanced mixer, such leakage should be zero. But mismatch in circuits exist and cause LO leakage.
What is meant by superheterodyne receiver?
A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency.
How does a direct-conversion receiver work?
Direct-conversion receivers convert an RF signal to a 0-Hz signal in one stage. The signal then enters a mixer along with a local-oscillator (LO) signal that is identical in frequency to the RF input signal. Thus, the input signal is converted to a 0-Hz signal that appears at the output of the mixer.
What is difference between homodyne and heterodyne?
In radio technology, the distinction is not the source of the local oscillator, but the frequency used. In heterodyne detection, the local oscillator is frequency-shifted, while in homodyne detection it has the same frequency as the radiation to be detected.
What is the advantage of Superheterodyning?
The advantages of superheterodyne receiver are many. An obvious advantage is that by reducing to lower frequency, lower frequency components can be used, and in general, cost is proportional to frequency. RF gain at 40 GHz is expensive, IF gain at 1 GHz is cheap as dirt.
What is RFIC mixer?
Microwave Mixers translate the frequency of electromagnetic signals to a higher/lower signal and are either also referred as Up or Down converters. RFIC Solutions provides wideband/narrowband mixers including passive (Diode) and active (pHEMT/MESFET).
What is RF downconverter?
an RF downconverter is a device which converts high radio frequency signal to low radio frequency signal is known as RF downconverter. Like RF upconverter, an RF downconverter will also have either one or two stages of mixing. Often RF downconverter is used in combination with RF LNA (Low Noise Amplifier).
What is the use of IF amplifier?
IF amplifiers can change the frequency levels in circuits that are too selective, difficult to tune, and unstable. They also help by changing the frequency levels in circuits which improve image display and tuning range. They are fixed frequency amplifiers which reject unwanted signals.
What is the heterodyne principle?
The principle that multiple frequencies applied to a nonlinear device produce new frequencies that are sums and differences of the applied frequencies and their harmonics.
What is direct conversion method?
Direct Conversion: Direct conversion is the implementation of the new system and the immediate discontinuance of the old system. This conversion is possible when: ADVERTISEMENTS: (a) The system is not replacing any other system.
What is the difference between TRF and superheterodyne receiver?
In a TRF receiver the high amplitude original frequency is demodulated at the detector stage. In TRF receiver, amplification is not constant over the tuning range. In superhet receiver amplification standard is constant since all the time it amplifies a constant frequency at the IF stages.
How does a zero if radio receiver work?
Fig 1: In the zero-IF architecture, the tuned signal is downconverted directly to baseband by mixing it with an LO at or near the carrier frequency, thus eliminating the need for an IF stage. (Source: Slideshare/LinkedIn, “Receiver Design”)
How does a zero IF DSP receiver work?
In the zero-IF receiver the analog signal is mixed to baseband and two converters sample the I and Q streams with the signal centered about DC.
What do you call a zero if transceiver?
The transceiver based on this zero IF architecture is known as zero IF transceiver . • All the filtering is carried out at baseband and hence analog filtering used in heterodyne architecture is alleviated here. Digital filters are easier to design. Moreover they are less expensive compare to RF/IF analog filters.
What are the different types of zero frequency receivers?
There are three common types of receiver architectures viz. heterodyne, super-heterodyne and homedyne. • Heterodyne uses one mixer to convert modulated RF to modulated IF and later the modulated IF is converted to IQ signals with zero frequency using IQ demodulator.