Topic
Absolute gain
About: Absolute gain is a research topic. Over the lifetime, 85 publications have been published within this topic receiving 1187 citations.
Papers published on a yearly basis
Papers
TL;DR: In this paper, a planar antenna array with a homogeneous spherical Teflon lens was proposed for wide scan-angle antennas at millimeter-wave frequencies with a special focus on ease of manufacturing and reliability.
Abstract: A new approach to wide scan-angle antennas at millimeter-wave frequencies is introduced with special focus on ease of manufacturing and reliability. The system is composed of planar feed antennas (tapered-slot antennas), which are positioned around a homogeneous spherical Teflon lens. Beam scanning can be achieved by switching between the antenna elements. The spherical-lens system is analyzed through a combined ray-optics/diffraction method. It is found that a maximum efficiency of 50%-55% can be achieved using Teflon, Rexolite, or quartz lenses. The efficiency includes taper, spillover, and reflection loss. Calculations also indicate that the maximum lens diameter is 30-40 /spl lambda//sub 0/, which results in a maximum directivity of 39.5-42 dB. Measurements done on a single-element feed and a 5-cm Teflon lens agree very well with theory and result in a 3-dB beamwidth of 5.5/spl deg/ and better than -20-dB sidelobe levels at 77 GHz. Absolute gain measurements show a system efficiency of 46%-48% (including dielectric loss). A 23- and 33-element antenna array with a scan angle of /spl plusmn/90/spl deg/ and a -3.5- and -6-dB crossover, respectively, in the far-field patterns was also demonstrated. The 23-element array resulted in virtually no gain loss over the entire 90/spl deg/ scan angle. This represents, to our knowledge, the first wide scan-angle antenna at millimeter-wave frequencies.
254 citations
TL;DR: In this paper, a generalized design of AGC circuits with constant settling time is described, where the major components of the AGC circuit are modeled and the criteria to obtain a gain settling time independent of the absolute gain are determined.
Abstract: The generalized design of Automatic Gain Control (AGC) circuits that have constant settling time is described. Each of the major components of the AGC circuit is modeled and the criteria to obtain a gain settling time independent of the absolute gain are determined. The method developed works with arbitrary monotonic nonlinear functions in the gain control characteristic of the variable gain amplifier. Several AGC circuits are simulated at the behavioral level to show the benefits of the technique developed.
174 citations
TL;DR: In this paper, a generalized three-antenna approach is proposed for determining power gain and polarization of antennas at reduced range distances, and the required data are obtained by an extrapolation technique which includes provisions for rigorously evaluating and correcting for errors due to proximity and multipath interference effects.
Abstract: A new technique is described for determining power gain and polarization of antennas at reduced range distances. It is based on a generalized three-antenna approach which, for the first time, permits absolute gain and polarization measurements to be performed without quantitative a priori knowledge of the antennas. The required data are obtained by an extrapolation technique which includes provisions for rigorously evaluating and correcting for errors due to proximity and multipath interference effects. The theoretical basis provides a convenient and powerful approach for describing and solving antenna measurement problems, and the experimental method employed illustrates the utility of this approach. Examples of measurements are included which exhibit errors in gain as small as \pm0.11 dB ( 3\sigma ).
160 citations
1 Jun 1967
TL;DR: In this article, the two-antenna method is considered to be essentially an insertions-loss measurement (with many additional problems and sources of error), and this concept is used to derive a working formula that is suitable for high-accuracy gain measurements.
Abstract: To calibrate antennas for state-of-the-art field-strength measurements above 1 GHz, standard antennas are needed that have gain values known to within ±0.1 dB. Since this requirements exceeds the verified accuracy of calculated gain values, these standards must be established by making absolute gain measurements. The discussion primarily concerns absolute gain measurements for horn antennas by the two-antenna method. However, much of the discussion is pertinent to high-accuracy field-strength measurements in general. The two-antenna method is considered to be essentially an insertions-loss measurement (with many additional problems and sources of error), and this concept is used to derive a working formula that is suitable for high-accuracy gain measurements. The two most intractable problems-- insufficient antenna separation and multipath interference--are discussed in detail. Some important experimental details are included that have previously been overlooked or inadequately discussed, and it is concluded that previous error estimates of less than ±0.1 dB for horn-gain measurements have been somewhat optimistic. To facilitate the design and evaluation of high-accuracy gain measurements, some simple terms, concepts, and formulas are provided that are useful in analyzing multipath interference.
47 citations
TL;DR: In this article, a modified microstrip Franklin array antenna (MFAA) is proposed for short-range radar applications in vehicle blind spot information systems (BLIS), which is shown that the radiating performance can be improved by increasing the number of radiators in the MFAA structure and assigning appropriate values to the antenna geometry parameters.
Abstract: A modified microstrip Franklin array antenna (MFAA) is proposed for short-range radar applications in vehicle blind spot information systems (BLIS). It is shown that the radiating performance [i.e., absolute gain value and half-power beamwidth (HPBW) angle] can be improved by increasing the number of radiators in the MFAA structure and assigning appropriate values to the antenna geometry parameters. The MFAA possesses a high absolute gain value (>10 dB), good directivity (HPBW 80°) in the H-plane at an operating frequency of 24 GHz. Moreover, the 10-dB impedance bandwidth of the proposed antenna is around 250 MHz. The MFAA is, thus, an ideal candidate for automotive BLIS applications.
43 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2020 | 3 |
| 2019 | 4 |
| 2018 | 3 |
| 2017 | 4 |
| 2016 | 3 |