This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/JACE.16991 This article is protected by copyright. All rights reserved DR SUBODH GANESANPOTTI (Orcid ID : 0000-0002-6784-094X) Article type : Article Crystal Structure, Phonon Modes, and Bond Characteristics of AgPb 2 B 2 V 3 O 12 (B=Mg, Zn) Microwave Ceramics Rakhi M. and Subodh G.* Department of Physics University of Kerala Thiruvananthapuram-695581 Kerala, India. *gsubodh@gmail.com ABSTRACT AgPb 2 B 2 V 3 O 12 (B=Mg, Zn) ceramics with low sintering temperature were synthesized via the conventional solid-state reaction route. Rietveld refinements of the X-ray diffraction patterns confirm cubic symmetry with space group d. The number of observed vibrational modes and those  3 predicted by group theoretical calculations also confirm the d space group. At the optimum  3 sintering temperature of 750 o C/4h, AgPb 2 Mg 2 V 3 O 12 has a relative permittivity of 23.3 , ± 0.2 unloaded quality factor ( ) of 26,900 GHz ( ) and temperature coefficient   ×  ± 500  = 7.57 GHz of resonant frequency of 19.3 ppm/ o C, while AgPb 2 Zn 2 V 3 O 12 has the corresponding values of ± 1 Accepted Article