Abstract: A harmonic filter for filtering a plurality of frequency components from an input signal comprises a phase shifter for generating an in-phase signal and a quadrature-phase signal according to the input signal; and a plurality of polyphase filter networks coupled in series. The first polyphase filter network in the series is coupled to the phase shifter for receiving the in-phase and quadrature-phase signals. Each polyphase filter network is for filtering a corresponding one of the frequency components from the input signal.

Abstract: Multistage RF transmitter and receiver circuits may use independently variable RF and IF local oscillators, allowing the RF and IF local oscillator frequencies for a given RF channel to be selected to have a large common factor with respect to the reference oscillator used by the local oscillator circuits, thus allowing the use of small divisor numbers in the local oscillator circuits and reducing phase noise. Independent high-side and low-side RF local oscillators may be provided and selectively used depending on the RF channel to be transmitted or received.

Abstract: Multistage RF transmitter and receiver circuits may use independently variable RF and IF local oscillators, allowing the RF and IF local oscillator frequencies for a given RF channel to be selected to have a large common factor with respect to the reference oscillator used by the local oscillator circuits, thus allowing the use of small divisor numbers in the local oscillator circuits and reducing phase noise. Independent high-side and low-side RF local oscillators may be provided and selectively used depending on the RF channel to be transmitted or received.

Abstract: A signal is applied to the body of a MOSFET to enhance the transconductance of the MOSFET. The signal applied to the body of the MOSFET has essentially the same waveform as an input signal supplied to the gate of the MOSFET, and is shifted by approximately 180 degrees with respect to the input signal. The signal applied to the body of the MOSFET may be provided by a phase-adjusting feedback circuit that generates the signal from a signal representing the output of the MOSFET.

Abstract: First, second, third, and fourth resistors are coupled to first, second, third, and fourth capacitors. A first positive in-phase terminal is coupled to the first resistor and the first capacitor. A first negative in-phase terminal is coupled to the fourth resistor and the fourth capacitor. A positive quadrature-phase terminal is coupled to the second resistor and the first capacitor. A second positive in-phase terminal is coupled to the first resistor and the second capacitor. A second negative in-phase terminal is coupled to the fourth resistor and the third capacitor. A negative quadrature-phase terminal is coupled to the third resistor and the fourth capacitor. The first and fourth resistors, the second and third resistors, the first and fourth capacitors, and the second and third capacitors are equal distances from and on a same side of respective axes, and are equal distances from and on opposite sides of a symmetry axis.

Abstract: A modular headboard for a bedstead includes an upper headboard section and a lower headboard section selectively coupled together for convenient storage and transportation. The upper headboard section includes laterally-spaced, vertically-extending upper post sections and a headboard panel extending therebetween. The lower headboard section includes corresponding lower post sections, with cross rails extending between the lower post sections. A laterally-extending slat overlaps adjacent edges of the upper and lower headboard sections to facilitate alignment of the upper and lower headboard sections, and is secured to the headboard sections to form a stable headboard.

Abstract: A signal is applied to the body of a MOSFET to enhance the transconductance of the MOSFET. The signal applied to the body of the MOSFET has essentially the same waveform as an input signal supplied to the gate of the MOSFET, and is shifted by approximately 180 degrees with respect to the input signal. The signal applied to the body of the MOSFET may be provided by a phase-adjusting feedback circuit that generates the signal from a signal representing the output of the MOSFET.

Abstract: A speaker stacking structure includes a speaker, the speaker having two bearing walls at two sides of the speaker cabinet thereof, a plurality of locating blocks respectively symmetrically fastened to the bearing walls of the speaker, each locating block having a plughole, and a plurality of fastening members insertable into the plugholes of the locating blocks to join two speakers in a stack.

Abstract: The present invention provides an improved multimedia storage tray including at least two support rails that are independent or separate, i.e. not directly connected. The support rails advantageously are identical in shape with each generally including a top surface having a lower surface and a raised ledge having an edge and a plurality of divider walls. The support rails are adapted to be attached to a furniture surface by a securing means in parallel, spaced apart, physically non-contacting relationship to each other. The divider walls are spaced apart substantially along the length of each support rail and cooperate with the top surface to provide storage spaces that accommodate different sized multimedia. The storage tray may be sold to the public already assembled in a furniture piece or sold directly to the do-it-your consumer as an after-market kit.

Abstract: Multistage RF transmitter and receiver circuits may use independently variable RF and IF local oscillators, allowing the RF and IF local oscillator frequencies for a given RF channel to be selected to have a large common factor with respect to the reference oscillator used by the local oscillator circuits, thus allowing the use of small divisor numbers in the local oscillator circuits and reducing phase noise. Independent high-side and low-side RF local oscillators may be provided and selectively used depending on the RF channel to be transmitted or received.

Abstract: A drawer stop device for use in furniture assemblies, such as dressers, cabinets, hutches, night tables, coffee tables, desks, entertainment centers and the like having drawers therein, the device includes a cam member configured for attachment to the underside of a drawer, the cam having a rearwardly and downwardly front facing cam surface, and a cantilever arm having a front mounting section configured for attachment to the lower frame member of the drawer opening and a rear deflectable section terminating in a free end, the deflectable section having an upwardly extending curved surface between the free end and the mounting section, wherein the arm when attached to the frame member of the drawer opening and cam when attached to the underside of the drawer are configured such that the cantilever arm hump is positioned in the path of travel of the front cam surface of the cam when the drawer is opened and to frictionally engage the cam when the drawer is at its extended normal open position from the opening

Abstract: An audio mixer includes a console, which has a base with an indication face, and different sizes of mounting holes and knob holes, a sound signal processing unit mounted inside the console, a sound signal input zone, which defines multiple sound signal input blocks and has connectors respectively mounted in the sound signal input blocks corresponding to the mounting holes of the console, a sub-control zone, which divides multiple sub-control blocks and has sub-control knobs respectively mounted in the sub-control blocks and the knob holes of the console and electrically connected to the sound signal processing unit, and a main control zone, which defines a main control block, and has an indication provided in the main control block and a main control knob greater in size than the sub-control knobs and electrically connected to the sound signal processing unit and disposed above the indication face of the console.

Abstract: First, second, third, and fourth resistors are coupled to first, second, third, and fourth capacitors. A first positive in-phase terminal is coupled to the first resistor and the first capacitor. A first negative in-phase terminal is coupled to the fourth resistor and the fourth capacitor. A positive quadrature-phase terminal is coupled to the second resistor and the first capacitor. A second positive in-phase terminal is coupled to the first resistor and the second capacitor. A second negative in-phase terminal is coupled to the fourth resistor and the third capacitor. A negative quadrature-phase terminal is coupled to the third resistor and the fourth capacitor. The first and fourth resistors, the second and third resistors, the first and fourth capacitors, and the second and third capacitors are equal distances from and on a same side of respective axes, and are equal distances from and on opposite sides of a symmetry axis.

Abstract: A harmonic filter for filtering a plurality of frequency components from an input signal comprises a phase shifter for generating an in-phase signal and a quadrature-phase signal according to the input signal; and a plurality of polyphase filter networks coupled in series. The first polyphase filter network in the series is coupled to the phase shifter for receiving the in-phase and quadrature-phase signals. Each polyphase filter network is for filtering a corresponding one of the frequency components from the input signal.

Abstract: An image rejection mixer includes an in-phase mixer for mixing a received RF signal with an in-phase reference signal to produce a current mode in-phase mixed signal and a quadrature-phase mixer for mixing the received RF signal with a quadrature-phase reference signal to produce a current mode quadrature-phase mixed signal, the quadrature-phase reference signal and the in-phase reference signal having a substantially orthogonal phase difference. A polyphase filter network is coupled to the current mode outputs of the in-phase mixed signal and the current mode quadrature-phase mixed signal. An inductor is coupled between an output of the polyphase filter network and a supply voltage to convert an output of the image rejection mixer to a voltage mode signal.

Abstract: A speaker stacking structure includes a speaker, the speaker having two bearing walls at two sides of the speaker cabinet thereof, a plurality of locating blocks respectively symmetrically fastened to the bearing walls of the speaker, each locating block having a plughole, and a plurality of fastening members insertable into the plugholes of the locating blocks to join two speakers in a stack.

Abstract: A speaker box mounting structure includes a holder base having a mounting plate for fastening to a wall or ceiling, a swivel arm set coupled to the holder base and adjustable relative to the holder base to a desired direction and angle, a coupling unit coupled to the swivel arm set, the coupling unit having a base, a coupling portion disposed at the base, and two stop faces disposed at two sides of the coupling portion and defining a contained angle, and a speaker box having a coupling portion coupled to the coupling portion of the coupling unit, and two stop faces disposed at two sides and respectively stopped against the stop faces of the coupling unit.

Abstract: A megaphone includes a speaker housing, a centric tube, and an illuminating device. The speaker housing has a mouth portion, a head portion connected to the mouth portion, and a power supply. The centric tube has a tube body, a coupling portion connected to a midsection of the speaker housing, and a lamp mount formed at a front portion of the tube body. The illuminating device is mounted on the lamp mount of the centric tube, having a plurality of light emitting diodes (LEDs) that can be electrically connected with the power supply of the speaker housing to generate illumination.