Rammeantenne

En rammeantenne (loop-antenne) er en radioantenne, der består af en loop (ring) eller spole af metaltråd eller metalbånd, metalrør, eller en anden elektrisk leder, som typisk er energifødet fra en balanceret elektrisk kilde eller belastet af en balanceret belastning.

En rammeantenne dækker over flere forskellige antennetyper, der bl.a. har forskellige bølgelængdeomkredse og om den evt. anvender en ferritkerne, kaldes den for en helbølge rammeantenne og en ferritantenne.^[1]^[2]^[3]

Denne artikel vedrører rammeantenner, der har en omkreds på mere end 30% af en bølgelængde til typisk omkring én bølgelængde.

^ antenna-theory.com: Small Loop Antennas, The Loop Antenna Citat: "...The [small] loop antenna feed point does not matter too much - it can be anywhere along the loop perimeter...Note that a balun may be needed...The one-wavelength perimeter loop antenna behaves like a folded dipole antenna, with an impedance that is higher than that of a half-wavelength dipole antenna...", backup. antenna-theory.com: Welcome to Antenna-Theory.com! Citat: "...I am a practicing antenna engineer, with a PhD in antennas and I have worked for many years in defense, university and the consumer electronics field as an antenna engineer. My dissertation in pdf form is available here: Antenna Arrays: Performance Limits and Geometry Optimization...", backup
^ ece.mcmaster.ca: LECTURE 12: Loop Antennas Citat: "...Loop antennas are usually classified as electrically small (C < λ/3) and electrically large (C ≈ λ). Here, C denotes the loop’s circumference...As the circumference of the loop increases, the [radiation] pattern maximum shifts towards the loop’s normal, and when C≈λ, the maximum of the pattern is alongthe loop’s normal...", backup
^ W5QJR, Ted Hart, robkalmeijer.nl: Small, high-efficiency loop antennas Citat: "...polarization component radiated by the [small] loop lies in the plane of the loop...Here's the bad news - the [small] loop is the equivalent of a high-Q tuned circuit, which means it has a narrow bandwidth...A power input to the antenna of 500 W will produce voltages of up to 30,000 V...", backup

[at-1] tenna-theory.com: Small Loop Antennas, The Loop Antenna Citat: "...The [small] loop antenna feed point does not matter too much - it can be anywhere along the loop perimeter...Note that a balun may be needed...The one-wavelength perimeter loop antenna behaves like a folded dipole antenna, with an impedance that is higher than that of a half-wavelength dipole antenna...", backup. antenna-theory.com: Welcome to Antenna-Theory.com! Citat: "...I am a practicing antenna engineer, with a PhD in antennas and I have worked for many years in defense, university and the consumer electronics field as an antenna engineer. My dissertation in pdf form is available here: Antenna Arrays: Performance Limits and Geometry Optimization...", backup

[mcmaster-2] .mcmaster.ca: LECTURE 12: Loop Antennas Citat: "...Loop antennas are usually classified as electrically small (C < λ/3) and electrically large (C ≈ λ). Here, C denotes the loop’s circumference...As the circumference of the loop increases, the [radiation] pattern maximum shifts towards the loop’s normal, and when C≈λ, the maximum of the pattern is alongthe loop’s normal...", backup

[3] W5QJR, Ted Hart, robkalmeijer.nl: Small, high-efficiency loop antennas Citat: "...polarization component radiated by the [small] loop lies in the plane of the loop...Here's the bad news - the [small] loop is the equivalent of a high-Q tuned circuit, which means it has a narrow bandwidth...A power input to the antenna of 500 W will produce voltages of up to 30,000 V...", backup

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