| Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board -> Monitor Keywords |
|
|
 
Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit boardMobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070273602, Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to the field of communications devices, and more particularly, to mobile wireless communications devices and related methods. BACKGROUND OF THE INVENTION [0002] Cellular communication systems continue to grow in popularity and have become an integral part of both personal and business communications. Cellular telephones allow users to place and receive phone calls most anywhere they travel. Moreover, as cellular telephone technology is increased, so too has the functionality of cellular devices. For example, many cellular devices now incorporate Personal Digital Assistant (PDA) features such as calendars, address books, task lists, calculators, memo and writing programs, etc. These multi-function devices usually allow users to wirelessly send and receive electronic mail (email) messages and access the internet via a cellular network and/or a wireless local area network (WLAN), for example. [0003] As the functionality of cellular communications devices continues to increase, so too does demand for smaller devices that are easier and more convenient for users to carry. As any circuit boards and electronic components thereon are reduced in size and placed closer together, including antenna and microphone components, various electronic components can pick up conductive energy and create interference within the system. [0004] Many of the designs include an RF metal shield secured onto the printed circuit board, and surrounding and isolating different RF components, including transceiver chip sets such as multi-chip modules, which are secured on the circuit board within the housing. The RF metal shield encloses these components and chip sets. Some of the RF components or chip sets radiate RF energy to other chips or components that are in close proximity from electromagnetic coupling through the RF metal shield. This type of electromagnetic coupling (EMC) or electromagnetic interference (EMI) coupling causes interference to the RF circuits, and degrades RF performance, such as receiver sensitivity. Thus, the RF metal shield that is supposed to shield the components from extraneous RF energy can in and of itself create electromagnetic coupling problems with different RF components that are supposed to be shielded within the RF shield. BRIEF DESCRIPTION OF THE DRAWINGS [0005] Other objects, features and advantages will become apparent from the detailed description which follows when considered in light of the accompanying drawings in which: [0006] FIG. 1 is a schematic block diagram of an example of a mobile wireless communications device configured as a handheld device that can be used and illustrating basic internal components thereof. [0007] FIG. 2 is a front elevation view of the mobile wireless communications device of FIG. 1. [0008] FIG. 3 is a schematic block diagram showing basic functional circuit components that can be used in the mobile wireless communications device of FIGS. 1-2. [0009] FIG. 4 is front elevational view of the mobile wireless communications device having the front cover removed to illustrate an example of RF circuitry, power amplifier, surface mounted microphone and noise isolation components associated thereof. [0010] FIG. 5 is a fragmentary, isometric drawing of a prior art RF metal shield covering an RF transceiver on a printed circuit board. [0011] FIG. 6 is a fragmentary, isometric drawing of an RF metal shield that includes an RF absorber formed as absorbing material positioned at an opening of the RF metal shield to aid in reducing RF energy radiated from an RF component such as part of an RF transceiver chip set into the RF metal shield and causing electromagnetic coupling or electromagnetic interference with other portions of the RF components or chip set within the RF metal shield. [0012] FIG. 7 is a fragmentary side elevation drawing of the RF metal shield and RF absorbing material positioned at an opening within the RF metal shield and covering a portion of an RF transceiver multi-chip module. [0013] FIG. 8 is another embodiment showing the RF metal shield and the RF absorber formed as a long and narrow slot on the RF metal shield to reduce RF coupling. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0014] Different embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown. Many different forms can be set forth and described embodiments should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art. Like numbers refer to like elements throughout. [0015] A mobile wireless communications device includes a housing and circuit board carried by the housing and having RF circuitry comprising at least one RF component, and a plurality of other components mounted on the circuit board. An RF metal shield is secured to the circuit board and surrounds and isolates the at least one RF component and plurality of other components within the RF metal shield. An RF absorber is positioned adjacent an area of the RF component that radiates energy to aid in reducing any energy radiated from the RF component into the RF metal shield. As a result, the electromagnetic coupling or interference with other portions of the RF component or other components within the RF metal shield is reduced. [0016] The RF shield, in one non-limiting example, has an opening at an area of the RF component that radiates energy. The RF absorber is formed as an RF absorbing material positioned at the opening of the RF metal shield. This RF absorbing material could be formed as a ferrite material, and preferably as a planar sheet that could be secured by adhesive tape to the RF metal shield. The RF absorber could also be formed as a longitudinal slot positioned over the area of the RF component that radiates RF energy. [0017] In another non-limiting example, the RF component can be formed as an RF chip set and preferably as a transceiver chip set that could be formed as a transmitter chip, receiver chip and local oscillator chip. The RF absorber can be positioned adjacent the transmitter chip. The RF circuitry could also be operative for generating Global System for Mobile (GSM) communications packet bursts. The RF circuitry could also include an RF transceiver, multi-chip module and associated RF components. [0018] A method aspect is also set forth. [0019] A brief description will now proceed relative to FIGS. 1-3, which disclose an example of a mobile wireless communications device, for example, a handheld portable cellular radio, which can incorporate the non-limiting examples of the various circuits. FIGS. 1-3 are representative non-limiting examples of the many different types of functional circuit components and their interconnection. [0020] Referring initially to FIGS. 1 and 2, an example of a mobile wireless communications device 20, such as a handheld portable cellular radio is first described. This device 20 illustratively includes a housing 21 having an upper portion 46 and a lower portion 47, and a dielectric substrate (i.e., circuit board) 67, such as a conventional printed circuit board (PCB) substrate, for example, carried by the housing. A housing cover (not shown in detail) would typically cover the front portion of the housing. The term circuit board 67 as used hereinafter can refer to any dielectric substrate, PCB, ceramic substrate or other circuit carrying structure for carrying signal circuits and electronic components within the mobile wireless communications device 20. The illustrated housing 21 is a static housing, for example, as opposed to a flip or sliding housing which are used in many cellular telephones. However, these and other housing configurations may also be used. Continue reading about Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board... Full patent description for Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board or other areas of interest. ### Previous Patent Application: Signal transmission line for high resolution multi-media interface Next Patent Application: Scanable sparse antenna array Industry Class: Communications: radio wave antennas ### FreshPatents.com Support Thank you for viewing the Mobile wireless communications device with reduced interfering rf energy into rf metal shield secured on circuit board patent info. IP-related news and info Results in 0.12749 seconds Other interesting Feshpatents.com categories: Novartis , Pfizer , Philips , Polaroid , Procter & Gamble , 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
