Recent experimental results in near-field antenna measurements

Plane-wave scattering-matrix theory of antennas and antenna-antenna interactions

“…Equations (14) and (12) Observing that \a\'^-Sir^Sp^jY^, we can now combine (11), (14a), (13), and (16) The quantity in brackets is a "polarization mismatch" factor, which according to the Schwarz inequality for complex vectors, attains its maximum value of unity for w, (1.6-18) Thus the condition for polarization match is expressed as a conjugate match of polarization indices. When (18) holds, we find from (17) and (8) _ 47T^Tlo|so,(K The power-gain and effective-area functions for a reciprocal antenna satisfy the wellknown reciprocity relation a,(K) =^G ,(-K), (1.6-21a) where X is the wavelength defined by 2 by Brown [20]. For mutually adjoint antennas the corresponding relations are…”

“…The concept of generalized reciprocity is not in itself new [4,5] [8][9][10][11]55]. Moreover, the error analysis required for rational design of facilities and for determination of accuracy in concrete measurement situations is approaching completion (Kanda [12], Yaghjian [13], Newell [14] [18].)…”

“…The free passage of waves is expressed by bi{m,K) -a2{m,K), b2{m,K) = ai{m,K). One may regard a scattering object as producing a perturbation of the properties of free space described in (13) or (14 The terms in (8) and (9) We adopt the conventional terminology, and will, without further comment, use the phrases "scattered power" and "scattered power density" as names for integrals of the type involved in (14) and for the corresponding Poynting's vector, respectively. Cross-terms of the type ignored in connection with (14) Here the tensors e and |X have their usual roles; T and v allow for the description of possible magnetoelectric properties of the medium [35].^(This last bit of generality may * In some of the recent literature, media described by equations of the form of (1) are called "bianisotropic."…”

“…(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) (With P = 0 (15) is essentially a basic and simple case of (43) or (46) in [1].) The integral appearing in this equation is the transmission integral (for transmission from left to right), and the scalar product in the integrand, SUm,K)S,o{m,K)^SUK)-S,,{K), (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) is called a coupling product. This marks the emergence of the central quantities involved in the antenna measurement techniques described here.…”

“…In order to establish some of the content of (15) (15) and set r = de^, the asymptotic form of (19) Splitting the coupling product between the factors Sq^and 1822 and using the Schwarz inequality, we next obtain as an upper bound for (21). Now, the pertinent value of the differential cross section for on-axis backscattering is obtained from (1.6-24) by replacing a in that equation by Sio(O) (and S22 by 822)-Combining the resulting expression with (22), (1.6-6), (1.6-19) and An important feature of (4) From (2)(3)(4)(5)(6)(7)(8)(9)(10) for the system 2-port, we obtain the expression 6^= aoMoVd -Mo-o'Tl), (3.2-1) which is a precise and complete version of (2-15 [6], [7], and for more general results, chapter III of this monograph.…”