text: Patent US20010035805 - Radio frequency amplifier with small distortion and superior isolation - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA radio frequency amplifier includes a waveguide filter positioned between a first and a second amplifier circuit, which reduces the distortion between the amplifier circuits. The waveguide includes a main body having a cavity....http://www.google.com/patents/US20010035805?utm_source=gb-gplus-sharePatent US20010035805 - Radio frequency amplifier with small distortion and superior isolationAdvanced Patent SearchPublication numberUS20010035805 A1Publication typeApplicationApplication numberUS 09/836,393Publication dateNov 1, 2001Filing dateApr 17, 2001Priority dateApr 20, 2000Also published asDE60101918D1, DE60101918T2, EP1148550A1, EP1148550B1, US6624692Publication number09836393, 836393, US 2001/0035805 A1, US 2001/035805 A1, US 20010035805 A1, US 20010035805A1, US 2001035805 A1, US 2001035805A1, US-A1-20010035805, US-A1-2001035805, US2001/0035805A1, US2001/035805A1, US20010035805 A1, US20010035805A1, US2001035805 A1, US2001035805A1InventorsShigetaka Suzuki, Akira TakayamaOriginal AssigneeAlps Electric Co., Ltd.Export CitationBiBTeX, EndNote, RefManClassifications (30), Legal Events (5) External Links: USPTO, USPTO Assignment, EspacenetRadio frequency amplifier with small distortion and superior isolation
  US 20010035805 A1Abstract
  A radio frequency amplifier includes a waveguide filter positioned between a first and a second amplifier circuit, which reduces the distortion between the amplifier circuits. The waveguide includes a main body having a cavity. Images(4) Claims(14)
  DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] Referring to FIGS. 1 to 5, a radio frequency amplifier preferably used in a millimeter-wave band (having frequency ranges from about 20 to about 40 GHz) transceiver or receiver and encompassing a preferred embodiment is described. A casing 1, preferably made of metal, such as brass or the like, absorbs heat like a heat sink. The casing 1 includes a storage part, such as the illustrated concave storage part 1 a having an opening at an upper part or side of the storage part la. Preferably, a side wall 1 b surrounds the storage part 1 a and a substantially rectangular concave cavity 1 d is preferably positioned at a bottom portion 1 c of the storage part 1 a. A pair of fastening holes 1 e are preferably positioned near the cavity 1 d. [0024] A circuit board 2, which is preferably a printed circuit board, includes a pair of holes 2 a and 2 b separated by a predetermined distance therebetween. A substantially rectangular through hole 2 c having a shorter length than the cavity 1 d of the casing 1 is positioned between holes 2 a and 2 b. A pair of mounting holes 2 d are positioned across from each other with the through hole 2 c positioned therebetween. A plurality of small holes 2 e surround sides of the through hole 2 c. [0025] Wiring patterns 3 a and 3 b made of conductive materials and a grounding pattern 4 made of a conductive material are positioned on a top surface of the circuit board 2. The through hole 2 c separates the top surface of the circuit board 2 into first and second regions R1 and R2. [0026] Portions of the wiring patterns 3 a and 3 b are positioned in the first and second regions R1 and R2. The wiring patterns 3 a and 3 b are positioned across from each other, with the through hole 2 c provided therebetween. Each wiring pattern 3 a and 3 b extend to substantially the middle of the through hole 2 c, and preferably are electrically coupled to probes 5 a and 5 b. The grounding pattern 4 is preferably formed around the side peripheries of the through hole 2 c and the mounting holes 2 d away from the probes 5 a and 5 b. The grounding pattern 4 is connected to a ground pattern formed on an entire back surface of the circuit board 2 by a connecting conductor provided through the small holes 2 e. [0027] The preferred circuit board 2 is preferably stored in the storage part 1 a such that the ground pattern is disposed on the bottom portion 1 c of the storage part 1 a. In this embodiment, the through hole 2 c provides access to the cavity 1 d provided on the bottom portion 1 c, and the probes 5 a and 5 b, which are positioned above the cavity 1 d and terminate near ends of the cavity 1 d. [0028] Amplifying elements 6 a and 6 b such as non-packaged or bare chips FETs are preferably inserted within the holes 2 a and 2 b of the circuit board 2. The amplifying elements 6 a and 6 b are secured or coupled to the bottom portion 1 c of the casing 1 through an adhesive, such as an electrically conductive adhesive. Wires 7 are preferably bonded to the amplifying elements 6 a and 6 b, and hence, the amplifying elements 6 a and 6 b are connected to the wiring patterns 3 a and 3 b positioned in the first and second regions R1 and R2, respectively. [0029] Various electrical components are preferably connected to the wiring patterns 3 a and 3 b formed or positioned in the first and second regions R1 and R2, respectively. Through these electrical components and the amplifying elements 6 a and 6 b, a first amplifier circuit 8 a that includes a bias circuit or the like is formed or positioned in the first region R1, and a second amplifier circuit 8 b that includes a bias circuit or the like is formed or positioned in the second region R2. [0030] A substantially rectangular main body 9, preferably made of metal, includes a cavity, preferably a concave cavity 9 a having an opening accessible from the underside or bottom surface of the main body 9. A side wall 9 b substantially surrounds the cavity 9 a and a plurality of concave portions 9 c or arches are positioned at the edge of the side wall 9 b to provide access to the cavity 9 a from the longitudinal sides of the main body 9. A pair of mounting holes 9 d are configured to receive fasteners 13, such as screws to couple the main body 9 to the circuit board 2. [0031] A lower opening of the main body 9 is preferably supported by the bottom portion 1 c of the casing 1. The cavity 9 a of the main body 9 is preferably aligned or opposed to the cavity 1 d of the casing 1. The main body 9 is coupled to the grounding pattern 4 on the circuit board 2 via fasteners 13, such as the illustrated screws. [0032] The main body 9 is grounded by the grounding pattern 4, and the circuit board 2 is held between the main body 9 and the bottom portion 1 c. Preferably, the probes 5 a and 5 b are aligned with one or at least one concave portion 9 c or arch of the main body 9, and thus, the electrical insulating property of the main body 9 is preserved. The probes 5 a and 5 b, the main body 9, and the bottom portion 1 c preferably comprise a waveguide filter 10. The main body 9 of the waveguide filter 10 is preferably arranged substantially parallel to the side wall 1 b defining the storage part 1 a. The main body 9 separates the storage part 1 a into first and second chambers 11 a and 11 b. In the first chamber 11 a, the first amplifier circuit 6 a is arranged. In the second chamber 11 b, the second amplifier circuit 6 b is arranged. The main body 9, which preferably forms part of the waveguide filter 10, provides electrical shielding between the first and second amplifier circuits 6 a and 6 b. [0033] A cover 12 which preferably comprises a metal plate includes a pair of mounting holes 12 a passing there through. The cover 12 is laid over the opening of the casing 1 to protect and electrically shield the first and second chambers 11 a and 11 b. A pair of fasteners 13, pass through the mounting holes 12 a of the cover 12, the mounting holes 9 d of the main body 9, and the mounting holes 2 d of the circuit board 2. The fasteners 13 are received by the fastening holes 1 e of the casing 1. The cover 12, the main body 9, and the circuit board 2 are mounted to the casing 1 using the screws in this embodiment, although other fasteners can be used in alternative embodiments. [0034] By securing the fasteners 13, preferably the interior of the cover 12 is brought into contact with the top surface of the main body 9, which preferably comprises part of the waveguide filter 10. Electrical shielding between the first and second chambers 11 a and 11 b and heat dissipation is improved by this substantially continuous or continuous ground that preferably interconnects the grounds on the top and bottom surfaces of the circuit board 2 to the cover 12 and the casing 1. By pressing the main body 9 downward using the cover 12, the circuit board 2 is securely held between the main body 9 and the bottom portion 1 c. Hence, the circuit board 2 is secure, and contact between the main body 9 and the grounding pattern 4 is ensured. Electrical insulation is preferably provided by the entire or substantially the entire bottom surface of the circuit board 2 interconnected to the grounded runs of the top surface of the circuit board 2, the grounded main body 9, and the grounded casing 1 and cover 12 With the above arrangement, a radio frequency amplifier according to a preferred embodiment is preferably assembled. [0035] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible. For example, the waveguide filter 10 is not limited to the above described structures, as the waveguide filter 10 can encompass any system or material that guides electromagnetic waves including, but not limited to, a hollow conductor, a solid dielectric, or a dielectric filled conductor. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Classifications U.S. Classification333/247, 333/208International ClassificationH03F1/32, H01L23/66, H01P5/103, H01P7/06, H03F3/68, H01P5/107, H05K9/00, H03F3/60, H03F1/00, H01P1/208Cooperative ClassificationH01L24/48, H01L24/49, H01L2924/1517, H01L2924/16195, H01L2924/15153, H01P7/06, H01L2224/49175, H01L2924/15165, H05K9/006, H01L2924/01057, H01P5/107, H01L23/66, H01L2224/48091, H01L2924/3025European ClassificationH05K9/00B33, H01P7/06, H01P5/107, H01L23/66Legal EventsDateCodeEventDescriptionNov 15, 2011FPExpired due to failure to pay maintenance feeEffective date: 20110923Sep 23, 2011LAPSLapse for failure to pay maintenance feesMay 2, 2011REMIMaintenance fee reminder mailedFeb 14, 2007FPAYFee paymentYear of fee payment: 4Apr 17, 2001ASAssignmentOwner name: ALPS ELECTRIC CO., LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SUZUKI, SHIGETAKA;TAKAYAMA, AKIRA;REEL/FRAME:011726/0891Effective date: 20010326Owner name: ALPS ELECTRIC CO., LTD. 1-7 YUKIGAYA, OTSUKA-CHO,Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SUZUKI, SHIGETAKA /AR;REEL/FRAME:011726/0891RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services