What is the basic difference between CW and FMCW Radar?
In a CW radar system, the transmitter and receiver are always operating. By using different patterns of changing frequency, such as frequency decreasing or increasing with time, a radar system with FMCW signals can accurately measure the distance to a target.
What is FMCW altimeter?
FMCW Radar is mostly used as Radar Altimeter in order to measure the exact height while landing the aircraft. The following figure shows the block diagram of FMCW Radar − FMCW Radar contains two Antennas − transmitting Antenna and receiving Antenna as shown in the figure.
How does a FMCW Radar work?
Instead of using time to measure distance (like TOF), FMCW technology emits a radar signal with a frequency that increases continuously to create a signal sweep. After being reflected by the process media surface, the signal’s echo will be picked up by the antenna.
What is the difference between FMCW and pulse Radar?
With FMCW technology, the transmitter emits a continous signal and determines the distance to the target by measuring the frequency difference between the emitted and the reflected signals. With pulse radar, the transmitter sends a pulse and then stops and waits for a reflection.
What is beat frequency in FMCW?
This frequency difference is called “beat frequency”. An occurring Doppler frequency would now move the frequency of the entire echo signal either up (moving towards the radar) or down (moving away from the radar). In this form of modulation, the receiver has no way to separate the two frequencies.
What is FM altimeter?
The FM-CW radar principle is used in the aircraft radio altimeter to measure height above the surface of the earth. The large backscatter cross section and the relatively short ranges required of altimeters permit low transmitter power and low antenna gain.
What is meant by MTI radar?
The moving target indicator (MTI) radar is a pulsed radar that uses the Doppler frequency shift as a means for discriminating moving targets from stationary clutter.
How FM is used in radar?
FM radar using passive transponders In the classic FM technique, the microwave source sweeps in frequency over time, usually with a linear ramp. By mixing the received signal with the outgoing signal, the difference frequency is proportional to the range at which the reflection occurred.
What is difference between MTI and pulse Doppler radar?
MTI RADAR uses low pulse repetition frequency while pulse Doppler uses high and medium pulse repetition frequency. MTI RADAR has no range ambiguity while range ambiguity may occur in pulse Doppler.
What is the application of FMCW radar?
The frequency modulated continuous wave (FMCW) radar principle is currently used in applications such as radioaltimeters, navigation systems [1] or in sensors for inhomogeneity identification on transmission lines [2] .
What is FMCW system?
An FMCW system is shown in Fig. 1 which consists of a transmitter, a receiver, a mixer and an analog-to-digital converter (A/D). A modulated signal is transmitted and received through antennas, and the transmitted and received signals are multiplied in the time domain and processed.
Why complex baseband architecture in FMCW?
The use of a complex-baseband architecture in FMCW radar systems enables various performance benefits without any penalty in ADC interface rate or memory/MIPS requirements on the DSP. In highly integrated CMOS radar solutions this architecture is implemented efficiently, at low cost and with low power.
Are FMCW radars the future of automotive safety?
By taking advantage of the emerging technologies, FMCW radars become feasible to realize signals generated and processed in real time for high performance automotive safety systems (Folster et al. 2005; Li et al. 2010).
How to overcome ghost targets in FMCW automotive radar systems?
For a typical FMCW automotive radar system, a new design of baseband signal processing architecture and algorithms is proposed to overcome the ghost targets and overlapping problems in the multi-target detection scenario. To satisfy the short measurement time constraint without increasing the RF fro …