Patent Number: 6,337,974

Title: Cellular mobile telephone terminal

Abstract: To achieve linear gain control (with a flatness of .+-.1 dB) over a widerange of 70 dB or greater using a single control voltage, an attenuator ofthe following configuration is provided in a radio frequency section of atransmitter of a cellular mobile telephone terminal. That is, a signalinputpart (34) and signal output part (35) for a radio frequency signalare connected by a signal line (51) containing at least two seriesvariable resistors (51 and 52); parallel variable resistors (53 and 54)are connected between a ground line (57) and the signal inputpart (34) andsignal outputpart (35), respectively; a gain control line (56) isconnected to the variable resistors (51, 52, 53, and 54); referencevoltage application parts (23, 27, 31, and 33) are connected to thevariable resistors (51, 52, 53, and 54), respectively; and a gain controlvoltage application part (19) is connected to each of the variableresistors (51, 52, 53, and 54) via the gain control line (56).

Inventors: Inamori; Masahiko (Takatsuki, JP), Motoyoshi; Kaname (Nishinomiya, JP), Tara; Katsushi (Kyoto, JP)

Assignee:

International Classification: H03G 1/00 (20060101); H03G 3/30 (20060101); H04B 7/005 (20060101); H01Q 011/12 ()

Expiration Date: 01/08/2014