harmonics
wavelength. The larger the frequency, the smaller the wavelength.
In physics the term harmonics is usually used. Note that the lowest-frequency mode also counts as a harmonic: it is simply the first one.
standing waves
Standing waves are formed when the reflected wave reinforces the initial wave at a resonant frequency. At other frequencies, the reflected wave tends to cancel out the initial wave. One example of a standing wave is when a guitar string is plucked. Due to the tension of the string, the length, and the mass, the string will vibrate at one frequency.
The sounds of all wind instruments are made by standing waves along some cavity- in this case the body of the clarinet. The body has some resonant frequency which will correspond to the frequency of the sound created. By changing the characteristics of the cavity (Opening valves and so on) this frequency can be changed, and a bunch of different notes can be played.
The polar pattern for a half lambda aerial is a toroidal (doughnut) shape with the aerial in the centre of the toroid when mounted in free space a half wave above the ground. The half wave is an omni-directional aerial and produces zero gain.
A standing wave can occur only at specific frequencies that are called natural frequencies.
When a circuit is said to be resonate it means a signal or wave that is being generated has some relationship with a reflected or feedback signal such that the generated signal is reinforced with the reflected or feedback signal. This reinforcing of the signal may cause a standing wave of constructive interference and required the generation of the signal and the reflection or feed back to be in phase or Coherent. if there is no phase coherency then it can be harder to achieve the standing wave of constructive interference. However is the Phase is detected and delay is compensated it can be achieved like in a laser ring gyro, which uses two resonate cavities that have there path length adapted to cope with heat expiation.
A standing wave pattern is a vibrational pattern created within a medium when the vibrational frequency of the source causes reflected waves from one end of the medium to interfere with incident waves from the source. This interference occurs in such a manner that specific points along the medium appear to be standing still. Because the observed wave pattern is characterized by points which appear to be standing still, the pattern is often called a standing wave pattern. Such patterns are only created within the medium at specific frequencies of vibration. These frequencies are known as harmonic frequencies, or merely harmonics. At any frequency other than a harmonic frequency, the interference of reflected and incident waves leads to a resulting disturbance of the medium which is irregular and non-repeating.
Of the same frequency.
A standing wave ratio of 1.5 is still a bit high. You should couple the antenna via some sort of antenna tuner and tune as close to 1:00 SWR. While t is possible to use a longwire antenna for CB reception purposes, the performance won't be too great. If, however, you are planning on transmitting, again, the longwire antenna should be coupled to the transmitter via some form of antenna tuner, to match impeadances, lower the SWR, and protect the final stage of the transceiver. A resonant long wire antenna only requires that the length of the wire is approximately resonant at the frequency of operation. For CB this means the wire must be a multiple of 11.1m (36ft 6.5 inches). Therefore, a three wave long wire would be 33.3 m (109' 9") and four-wave long wire would be 44.4m (146' 3") in length.
Standing advisory committee on radio frequency alocation.