If the received signal was 1 kHz below the LO signal frequency, then there would be the same 1 kHz IF output signal. Mixer will also produce a signal at sum frequency (about 48.2 GHz) and various other harmonic frequencies, but these signal components are either filtered or otherwise not significant in this application. When the mixer RF port signal is 1 kHz higher than the mixer LO signal frequency, there will be a sinusoidal signal at 1 kHz frequency at the mixer IF output. the mixer RF port signal from the receive antenna, frequency is 24.100001 GHz. The transmitted signal, and hence the receiver mixer LO signal, frequency is 24.1 GHz. The purpose of the transmitter path directional coupler is to take a sample of the transmitted signal and connect it to receive path mixer LO port.
![pcb weather radar pcb weather radar](https://www.distrelec.de/Web/WebShopImages/landscape_large/8-/01/Seeed-101990580-30172318-01.jpg)
An RF mixer can be understood as a non-linear component, which produces sum and difference frequencies of the LO and RF signals at its IF output port. RF mixer is a three port component whose ports are named typically Radio Frequency (RF), Intermediate Frequency (IF) and Local Oscillator (LO) port. Due to the directional coupler, most of the signal energy is connected to the transmit antenna but some of the energy is coupled to the receive path RF mixers. The transmitted oscillator signal is connected to the transmit antenna via a directional coupler. However, movement of the obstacle can be detected based on the Doppler shift in the received signal. If the waveform is unmodulated like in this project, it is not possible to measure the distance. If the waveform contains pulse or other modulation the radar can measure the distance to the obstacle based on the measured time of flight of the signal. When the transmitted wavefront meets an obstacle, some portion of the transmitted energy is scattered from the obstacle and can be received by the radar receive antenna. A radar operates by transmitting a signal using the transmit antenna. In this application, however, a simple continuous wave Doppler radar is built and the tuning input is not needed. The tuning voltage input, marked as FM input, of the module can be used to frequency modulate the VCO. The transmitted signal is generated by a voltage controlled oscillator (VCO) operating nominally at frequency range 24.050-24.250 GHz. The block diagram of the radar module RF components is shown in Figure 1, which is an excerpt from the module data sheet. A Doppler radar can measure for example speed of a ball, bicycle or a running person, which may turn out to be pretty entertaining among the sporty kids of the neighborhood. Of course, it is also important to make some kind of use of the final product. The most interesting thing, in my opinion was to learn new things and make electronics bits and pieces to work as planned. The aim of the project was to build a microwave Doppler radar by using a low cost radar module. Now that I have something to show I would like to share the project results and some insights into this interesting technology with other Elektor readers. Since then I have developed an idea of a hobby project on a microwave radar. After that I have also noticed product news from various companies about small, low cost radar chips and modules. IntroductionĪ couple of years ago I read an article about small radars by Gregory L. Mostly cloudy, with a high near 65.Build an experimental microwave Doppler radar by using a low-cost radar transceiver module. Wednesday: Mostly sunny, with a high near 65.
![pcb weather radar pcb weather radar](https://tiles.windy.com/tiles/v10.0/darkmap-retina/9/134/211.png)
Tuesday Night: Partly cloudy, with a low around 47. Monday Night: Mostly clear, with a low around 39. M.L.King Day: Sunny, with a high near 54. Sunday Night: Mostly cloudy and breezy, with a low around 39. Breezy, with a west northwest wind between 22 and 28 mph, with gusts as high as 33 mph. Sunday: Mostly cloudy, with a high near 53.
![pcb weather radar pcb weather radar](https://nauticalmarinebd.com/wp-content/uploads/2020/09/C-PLATH-NAVITWIN-II-COMPASS-MONITOR-TYPE-4795.jpeg)
Breezy, with a south southeast wind 20 to 25 mph becoming west. Southeast wind 8 to 11 mph increasing to between 18 and 21 mph. Tonight: Partly cloudy, with a low around 50. This Afternoon: Sunny, with a high near 64. Forecast Valid: 1pm CST Jan 14, 2022-6pm CST Jan 20, 2022