The H and V levels of the patch antenna work very similarly. Patch antennas with lower gain have a large beamwidth but a short distance. If you add gain to an antenna, these beam widths will become narrower, but they will go further. The width of the antenna beam determines the expected strength of the signal, taking into account the direction and distance of the beam from an antenna. The beam width varies taking into account various factors such as antenna type, design, orientation, and radio frequency. Understanding beam width and its impact on a test environment is essential for accurate and repeatable testing. Let`s start with this fun fact: antennas are based on mathematical theory. There are 4 electrical properties of antennas that influence each other: The horizontal plane (also called azimuth) is like the pattern of the antenna to be seen from the sky. The width of this angle is called the horizontal beam width. An anechoic test chamber is a non-reflective, non-reflective space that completely adsorbs all reflections of electromagnetic waves.

When an antenna is tested in this chamber, all external noise and electromagnetic waves are isolated, so that the test results are accurate and describe only the intended test subject. Yay. In order to allow possible direct measurement of parameters from the waveforms of the oscilloscope, it was common to use widths that are also measured at half-voltage points (−6 dB). These half-voltage points do not have the same position as half of the power points in the antenna diagram diagram. Assuming the impedance is the same, half the voltage causes half of a current. Half the current multiplied by half the voltage gives a quarter of the power, expressed in decibels – 6 dB. If RF voltage measurements are to be used to estimate the beam width of an antenna, then the 0.707 voltage points characterize half the width of the power beam. The entire range of an antenna faces incident electromagnetic waves when it is received, while only part of the antenna receives the signal, called effective range. Let`s start with omnidirectional (or omnidirectional) antennas. Omnis get their name from the fact that their patterns are round.

Easy. 2] First zero beam width (FNBW) FNBW is the degree of angular distance from the main beam. It is located between the zero points of the main lobe of the antenna radiation pattern. This measurement can help assess antenna interference. The big change in omni models happens at level V when you increase the gain. A lower gain omni will be quite spherical, almost like a balloon. However, when you start increasing the gain of an omniantenna, the width of the vertical beam becomes flatter. See image below.

Other factors that need to be considered during testing are fields E and H. RF radiation consists of both magnetic fields (H) and electric fields (E), and these two field planes are always perpendicular to each other. This is important if an antenna is designed to radiate with a certain polarization. The polarization of an antenna corresponds to the plane E, although it also has a perpendicular plane H. The polarization of the antenna has a significant influence on the signal strength. As a first approximation, it is assumed that the side lobes of the antenna can be neglected and that the total power generated by the transmitter is concentrated in the main lobe. In order to correct the effects of this approximation with theoretical calculations, the term beam shape loss is introduced. The space is in 3 dimensions and difficult to transmit on a 2D technical sheet.

To give you the best radiation and reception characteristics of an antenna, let`s take the pattern at its maximum value and divide it vertically and horizontally into two halves. And that`s how you get the radiation pattern you see on most datasheets. In this chapter, we will discuss another important factor in the radiation pattern of an antenna known as beamwidth. In the radiation pattern of an antenna, the main lobe is the main beam of the antenna in which the maximum and constant energy radiated by the antenna flows. Since beam width is closely related to directivity and gain, changing beam width causes proportional changes in these two parameters. In addition, the signal-to-noise ratio (SNR), the ratio of signal strength to unwanted interference (noise), changes accordingly. If the beam width is reduced, the gain and directivity increase. This also favorably increases the signal-to-noise ratio (SNR). For this reason, narrow beamwidth antennas are a smart choice for long-range transmissions.

1] Half-power beam width (HPBW) is an angle between half-power points in the main lobe, measured at -3 dB. This is considered to be the part of the antenna output that has maximum coherence and utility, and is closely related to antenna amplification. When planning an antenna array, the HPBW is the point of intersection of adjacent sectors. You now understand antennas a little better and how the relationships between antenna frequency, gain, polarization, and beamwidth work. So let`s move on to the actual reading of the antenna models. Because directional antennas radiate in an expansion pattern, measuring and evaluating the output or reception gain in a particular direction can be difficult for an antenna. By analogy, consider that an inflated (and perfectly round) balloon is an omnidirectional antenna. Pressing the sides of the balloon together would give a shape similar to that of a directional antenna. Each antenna has a specific beamwidth pattern, but this pattern is not constant across all frequencies. For this reason, it is important to consider the operating frequency during testing to account for differences in beam width. Higher frequencies have a smaller wavelength; In general, higher frequencies have a narrower beamwidth and are more directed. The divergence of the beam is related to the frequency by a formula, so it is quite easy to account for these effects.

The H level of an omni really does not change, it will remain pretty round no matter what. But if you increase the profit of an Omni, you get a wider circle. Thus, a low-gain omni covers a smaller area than a high-gain omni. This antenna is vertically polarized. Polarization describes how sine waves propagate. Vertically polarized antenna sine waves move up and down, and horizontally polarized sine waves move left and right. For a full introduction to dual-polarization antennas and their benefits, read here. For the purposes of this article, you only need to know that if an antenna is dual-polarized, you may have additional beam widths given on the datasheet for each of the planes, and the patterns may show a small difference in their degree values for horizontally polarized elements compared to vertically polarized elements. Logarithmic-periodic antennas have a wide frequency bandwidth, while also being able to be designed to have adequate directionality.

As a rule, the width of the beam width of a log periodically depends on the length of the boom, the spacing of the elements, the taper and the number of elements. The beam width is generally used for half-power testing. This can be calculated based on the characteristics of the antenna and is often obtained from the manufacturer. Half the width of the antenna power beam, as well as the distance to the DUT, provide the information needed to set up a test environment. An online beamwidth coverage calculator is available. The last question you might ask yourself is why we use the 3 dB beam width line to read beam widths. Well, the 3 dB line indicates the beam width when the radio is half power. This is a point in the middle without power and full power that almost all antenna manufacturers have standardized. If you need help choosing a test antenna, calculating antenna beam width, or measuring beam width, contact A.H. Systems, Inc. If the direction and distance of an antenna are known, the beam width can also be used to determine the expected signal strength for the antenna. Amplification affects both the energy efficiency and directivity of the antenna and is therefore closely related to the beam width.

The width and gain of the beam have an inverse relationship. Decreasing the antenna bandwidth increases the gain. This is because reducing the beam width increases power transmission in a certain direction. Each antenna has different characteristics and directions. It is important to choose the appropriate antenna with the appropriate beamwidth for a particular test. In addition to beam width, factors such as resonant frequency, bandwidth, polarization, and gain play a role. No single antenna design can cover all aspects, so it is necessary to choose the best antenna for each test. Definition – “The effective area is the area of the receiving antenna that absorbs most of the energy from the incoming wavefront to the total surface of the antenna exposed to the wavefront.” Radiation patterns are a graphical representation of how an antenna radiates and receives energy in space.