However, cambro food carrier for the calculation of the free space propagation, the antenna must be

Frequencies above 1 GHz, are commonly referred to as microwaves. Our 23cm band, although is still in the UHF range, so our lowest microwave band. It is also the most popular among the microwave bands. Incidentally, it follows the 3cm band (10 GHz) in terms of popularity. 13cm and 6cm are less in demand. 9cm is not zugelass3n in all countries. The propagation characteristics of microwaves are at first glance similar to the first one 2m and in the 70 cm band. The spread is analogous to the optical cambro food carrier laws of reflection, diffraction and refraction.
Considering the free-space propagation (in the vacuum of space), it is found that the path loss increases with each doubling of frequency by 6 dB, assuming the same antenna gain. Expected rough the path attenuation in the 13cm band is thus 6 dB higher than the 23cm band, and it is 6cm again 6dB greater. This has nothing to do with any mysterious mind eating up the waves or destroyed in a mystical kind of energy in the vacuum. Whether 23cm or 6cm waves: the vacuum is lost nothing cambro food carrier of it. The energy is "diluted" due to the spread.
However, cambro food carrier for the calculation of the free space propagation, the antenna must be always taken into account. And since the antennas cambro food carrier are getting smaller with increasing frequency, cambro food carrier they can also collect less energy cambro food carrier than receiving antenna. For example, a dipole for 10 GHz is only half as large as 5 GHz, it therefore covers only a quarter of the surface, so only one quarter of the energy collecting (-6dB). But this greater path loss can be easily compensated with more antenna gain. If I'm doing it at the receiver means 6dB more, but if I am aware of the transmitting antenna, I come from, each with 3 dB to compensate for the higher attenuation with frequency doubling. So far, so good. However, a disadvantage of the course. The higher the antenna gain, the sharper directivity. In the commercial services plays that usually does not matter cambro food carrier (directional beam connection) or is even desirable (radar, satellite). But for us hams it has consequences. With strong bundling connections will be established only by agreement. CQ brings nothing more.
In general, the professionals have very different demands on their wireless connections as we amateurs. professionals in counts above all reliability. A wireless connection should be as trouble-free 100% of the time function. Overreach and spread capers are undesirable.
Just the opposite is asking us radio amateurs. We love the vagaries of wave propagation and look forward to compounds, to which one can not rely in the microwave region especially overreaches are called cambro food carrier by Ducts: waveguide in the atmosphere, formed by inversion layers. Use this Ducts we can bridge on VHF / UHF and SHF distances that would otherwise be impossible.
Unfortunately, come Ducts not anywhere on earth with equal frequency. While they are quite rare here in Central Europe, they are in other parts of the world to the agenda. Much to the chagrin of professionals with their directional cambro food carrier beam connections and radar. Warm water with little wind are ideal conditions.
But even without Ducts is the spread on the ground anything but a free-space propagation. In contrast to the space we are dealing not only with the topography, cambro food carrier but also with our atmosphere. Especially oxygen and water vapor absorbing our microwaves. cambro food carrier How do these additional damping effect, can be seen here. It looks very nice that there are several maxima. A very distinctive exists at 60 GHz. In this context, should be expected to atmospheric excess attenuation up to 16 dB per km. There are possible Funkverbingungen only a few km. An ideal band for tap-proof short distances, a nightmare for radio amateurs.
How does the atmospheric attenuation affects the propagation in our bands can be seen in the picture above. Light blue is the attenuation shown by the oxygen, the dark blue. Due to the water vapor Red is the combination of the two. As you can see, the adsorption cambro food carrier plays through the atmosphere to the 10 GHz band not a big role. But then it becomes critical. Already in the 24 GHz band, it is crucial cambro food carrier for DX connections. In particular, the damping due to the humidity (dark blue), while the adsorption not yet play a major role by the oxygen. cambro food carrier
Dry air can be found on high mountains and as it also contains large view distances are possible, they seem to be ideal locations for DX. Unfortunately, cambro food carrier there are on the lonely peaks another problem: in such large height ducts are rare. Fortunately normally prevail in Ducts but better conditions (drier air