JPH05347580A - Mobile communication system - Google Patents

Mobile communication system

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Publication number
JPH05347580A
JPH05347580A JP4154672A JP15467292A JPH05347580A JP H05347580 A JPH05347580 A JP H05347580A JP 4154672 A JP4154672 A JP 4154672A JP 15467292 A JP15467292 A JP 15467292A JP H05347580 A JPH05347580 A JP H05347580A
Authority
JP
Japan
Prior art keywords
amplifier
signal
frequency
signals
base station
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP4154672A
Other languages
Japanese (ja)
Inventor
Osamu Morita
理 森田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP4154672A priority Critical patent/JPH05347580A/en
Publication of JPH05347580A publication Critical patent/JPH05347580A/en
Withdrawn legal-status Critical Current

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  • Mobile Radio Communication Systems (AREA)

Abstract

PURPOSE:To provide a mobile communication system which can prevent such a case where the amplifier of a base station is saturated when the received signals of different frequencies are amplified in common by the amplifier. CONSTITUTION:The signals of different frequencies which are used for communication of many mobile stations 4 included in a radio wave area of a base station 1 are divided into a 1st signal group of the frequency which is usually used and a 2nd signal group of the frequency which is not usually used. Then the 1st signal group is amplified by a 1st amplifier 13 of the receiver side, and the 2nd signal group is amplified by a 2nd amplifier 14 of the smaller gain than the amplifier 13. These amplified signal groups are synthesized together and these synthetic signals of different frequencies are received by a controller 3 via a MODEM device 2. The levels of the received signals are individually detected. When the detected levels exceed a certain reference level, an instruction is given to the station 4 that is transmitting the signal of the frequency higher than the reference level. Thus the instructed station 4 switches its using frequency to another that is not usually used.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は移動通信システムに関す
る。近年、携帯電話機、自動車電話機等の移動局の需要
が増加するに伴い、移動局を制御する基地局を、多数設
置しなければならなくなっている。
FIELD OF THE INVENTION The present invention relates to mobile communication systems. With the recent increase in demand for mobile stations such as mobile phones and car phones, it has become necessary to install a large number of base stations for controlling the mobile stations.

【0002】基地局の設置場所はビル屋上の限定された
場所等であるために、その大きさを極力小さくしなけれ
ばならない。しかし、基地局には、通話チャネル毎に送
受信各々の増幅器を有する送受信装置を設けなければな
らないので、基地局が扱うチャネル数が多い場合は増幅
器の数が増え、全体のサイズが大きくなる。
Since the base station is installed in a limited place such as on the roof of a building, its size must be minimized. However, since the base station must be provided with a transmitter / receiver having amplifiers for transmission and reception for each communication channel, if the number of channels handled by the base station is large, the number of amplifiers increases and the overall size increases.

【0003】そこで、周波数分割多重化又は時分割多重
化技術により、送受信各々1つの増幅器で多数チャネル
の送受信信号を適正に増幅できる送受信装置を用いるこ
とによって、基地局を小型にすることが要望されてい
る。
Therefore, it is desired to downsize the base station by using a transmission / reception apparatus capable of properly amplifying transmission / reception signals of a large number of channels with one amplifier for each of transmission and reception by frequency division multiplexing or time division multiplexing technology. ing.

【0004】[0004]

【従来の技術】図4は従来の移動通信システムのブロッ
ク構成図である。この図において、1a〜1nは複数の
送受信装置である。各送受信装置1a〜1nは、ビル屋
上等に基地局として設置されるものであり、ケーブルに
よって主局の変復調装置2及び制御装置3に接続されて
おり、自己の電波エリア内の多数の移動局4a〜4mと
通信を行う。
2. Description of the Related Art FIG. 4 is a block diagram of a conventional mobile communication system. In this figure, 1a to 1n are a plurality of transmission / reception devices. Each of the transmission / reception devices 1a to 1n is installed as a base station on the rooftop of a building or the like, and is connected to the modem device 2 and the control device 3 of the main station by a cable, and a large number of mobile stations within its own radio area It communicates with 4a-4m.

【0005】この通信は、移動局4a〜4mに応じて異
なる各通話チャネルの通信信号の周波数を分割多重する
周波数分割多重化により行われる。制御装置3から送出
される各チャネルの異なる周波数の送信信号が変復調装
置2により変調された後、送受信装置1aの送信側増幅
器5aにより共通増幅され、アンテナ6aから電波送信
される。この電波送信された各チャネルの送信信号は、
送受信装置1aの電波エリア内の該当する周波数が割り
当てられた移動局4aで受信される。
This communication is performed by frequency division multiplexing for dividing and multiplexing the frequencies of the communication signals of the respective communication channels which differ depending on the mobile stations 4a to 4m. After the transmission signals of different frequencies of the respective channels sent from the control device 3 are modulated by the modulation / demodulation device 2, they are commonly amplified by the transmission side amplifier 5a of the transmission / reception device 1a and transmitted by the antenna 6a. The transmission signal of each channel transmitted by this radio wave is
The signal is received by the mobile station 4a to which the corresponding frequency within the radio wave area of the transmitter / receiver 1a is assigned.

【0006】一方、送受信装置1aの電波エリア内の多
数の移動局4aから送信された電波信号は、アンテナ7
aにより受信される。この各々周波数の異なる受信信号
は、受信側増幅器8aで共通増幅された後、変復調装置
2で復調され、制御装置3へ送られる。
On the other hand, the radio wave signals transmitted from a large number of mobile stations 4a within the radio wave area of the transmitter / receiver 1a are transmitted to the antenna 7
received by a. The reception signals having different frequencies are commonly amplified by the reception-side amplifier 8a, demodulated by the modulator / demodulator 2 and sent to the controller 3.

【0007】他の基地局の送受信装置1nにおいても自
己の電波エリア内の多数の移動局4mと同様に通信が行
われる。
The transmitter / receiver 1n of another base station communicates with the mobile stations 4m within its own radio wave area in the same manner.

【0008】[0008]

【発明が解決しようとする課題】ところで、上述したよ
うに各々周波数の異なるチャネルの送受信信号を、各々
1つの送受信増幅器で増幅する方式においては、基地局
に対する各移動局の距離が異なるので、受信信号の電界
レベルが異なる。
By the way, in the system in which the transmission / reception signals of channels having different frequencies are amplified by one transmission / reception amplifier as described above, the distance between each mobile station and the base station is different. The electric field levels of the signals are different.

【0009】即ち、基地局に近い移動局からの信号は、
そのレベルが大きいので、その信号を受信して増幅した
場合に、増幅器が飽和状態となり、高調波が生じ、これ
が他のチャネルの信号に影響を及ぼし、適正な通信が行
えなくなるといった問題がある。
That is, the signal from the mobile station close to the base station is
Since the level is large, when the signal is received and amplified, the amplifier is saturated and a harmonic is generated, which affects the signals of other channels, and there is a problem that proper communication cannot be performed.

【0010】本発明は、このような点に鑑みてなされた
ものであり、基地局の増幅器によって各々異なる周波数
の受信信号を共通増幅した際に増幅器が飽和状態となる
ことを防止することができる移動通信システムを提供す
ることを目的としている。
The present invention has been made in view of the above point, and it is possible to prevent the amplifiers from being saturated when the received signals of different frequencies are commonly amplified by the amplifiers of the base station. It is intended to provide a mobile communication system.

【0011】[0011]

【課題を解決するための手段】通信制御を司る主局に配
線接続された基地局と、基地局の電波エリア内の多数の
移動局とで交信される各々周波数の異なる各信号を、送
受信側各々1つの増幅器で共通増幅して通信を行う移動
通信システムにおいて、多数の移動局が通信を行うため
の各々異なる周波数の信号を、通常使用する周波数の第
1信号群と、通常使用しない周波数の第2信号群とに分
岐する分岐手段と、第1信号群を増幅する受信側の第1
増幅器と、第1増幅器よりも利得が小さく、かつ第2信
号群を増幅する受信側の第2増幅器と、第1及び第2増
幅器から出力される信号を合成する合成手段とを基地局
に設け、合成手段から出力される各々異なる多数の周波
数の信号を変復調装置を介して受信し、この受信された
信号のレベルを個々に検出し、この検出レベルがある基
準レベル以上となった場合に、基準レベル以上となった
周波数の信号を送出している移動局に対して、現在使用
中の周波数を前記した通常使用しない周波数に切り替え
る指示を行う制御装置を主局に設けて構成する。
[MEANS FOR SOLVING THE PROBLEMS] A base station wiredly connected to a main station that controls communication and a large number of mobile stations within a radio area of the base station transmit and receive signals of different frequencies. In a mobile communication system in which a single amplifier performs common amplification for communication, a plurality of mobile stations communicate signals of different frequencies with a first signal group of frequencies normally used and a frequency of frequencies not normally used. Branching means for branching into a second signal group, and a receiving-side first for amplifying the first signal group
The base station is provided with an amplifier, a second amplifier on the reception side that has a gain smaller than that of the first amplifier and that amplifies the second signal group, and a combining unit that combines the signals output from the first and second amplifiers. , Receiving signals of a large number of different frequencies output from the synthesizing means via a modulator / demodulator, individually detecting the levels of the received signals, and when the detected levels are above a certain reference level, The main station is provided with a control device for instructing a mobile station that is transmitting a signal having a frequency higher than the reference level to switch the currently used frequency to the frequency that is not normally used.

【0012】また、前記した基準レベルは、第1増幅器
が飽和状態となった際に出力される信号レベルとするの
が好ましい。
The reference level is preferably a signal level output when the first amplifier is in a saturated state.

【0013】[0013]

【作用】上述した本発明によれば、主局に設けられた制
御装置が基準レベル以上の信号を検出した場合に、この
検出された信号の周波数で通信を行っている移動局に対
して、現在使用中の周波数を通常使用しない周波数に切
り替える指示が行われ、この指示道理に移動局が周波数
の切り替えを行う。
According to the present invention described above, when the control device provided in the main station detects a signal having a level higher than the reference level, the mobile station communicating with the frequency of the detected signal is An instruction is given to switch the currently used frequency to a frequency that is not normally used, and the mobile station switches the frequency according to this instruction.

【0014】そして、移動局が通常使用していない周波
数の信号で通信を行うので、その周波数の信号が基地局
の分岐手段を介して第2増幅器で増幅されることにな
る。基準レベル以上となった周波数の信号では、第1増
幅器が飽和状態となって高調波が生じ、他の周波数の信
号に影響を及ぼすが、発明では、前記したように周波数
の切り替えによって第1増幅器よりも利得の小さい第2
増幅器で増幅されるようになるので、この際の増幅にお
いては、第1増幅器のように飽和状態となることはな
い。
Since the mobile station communicates with a signal of a frequency that is not normally used, the signal of that frequency is amplified by the second amplifier via the branching means of the base station. In the case of a signal having a frequency higher than the reference level, the first amplifier is saturated and a harmonic is generated, which affects signals of other frequencies. However, in the invention, the first amplifier is switched by switching the frequency as described above. Second gain with a smaller gain
Since it is amplified by the amplifier, the amplification at this time does not result in a saturated state unlike the first amplifier.

【0015】即ち、増幅器の飽和状態を防止することが
できるので、先に記述したように増幅器が飽和状態とな
って高調波が生じ、他の周波数の信号に影響を及ぼすこ
とがなくなる。
That is, since the saturation state of the amplifier can be prevented, as described above, the amplifier enters the saturation state and harmonics are generated, so that signals of other frequencies are not affected.

【0016】[0016]

【実施例】以下、図面を参照して本発明の一実施例につ
いて説明する。図1は本発明の一実施例による移動通信
システムのブロック構成図である。この図において図4
に示す従来例の各部に対応する部分には同一符号を付
し、その説明を省略する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a mobile communication system according to an embodiment of the present invention. In this figure
The same reference numerals are given to the portions corresponding to the respective portions of the conventional example shown in, and the description thereof will be omitted.

【0017】但し、主局には従来例で説明したように複
数の基地局が配線接続されるが、この図1においては1
つの基地局のみを示す。図1に示す基地局となる送受信
装置1は、送信側の増幅器5と、送信アンテナ6と、受
信アンテナ7と、ハイブリッド回路11,12と、受信
側の第1及び第2増幅器13,14とを具備して構成さ
れている。
However, although a plurality of base stations are hard-wired to the main station as described in the conventional example, in FIG.
Only one base station is shown. The transmitter / receiver 1 serving as a base station shown in FIG. 1 includes a transmitter-side amplifier 5, a transmitter antenna 6, a receiver antenna 7, hybrid circuits 11 and 12, and receiver-side first and second amplifiers 13 and 14. It is configured to include.

【0018】第1増幅器13は、第2増幅器14よりも
大きい利得を有するものであり、例えば第1増幅器13
の利得を20倍とすると第2増幅器14の利得は5〜1
0倍位に設定されている。
The first amplifier 13 has a larger gain than the second amplifier 14, and for example, the first amplifier 13 is provided.
, The gain of the second amplifier 14 is 5 to 1
It is set to 0 times.

【0019】また、第1増幅器13は、図2に示す各々
の通話チャネルの信号周波数f1 〜fz の内、周波数f
1 〜fm の受信信号を増幅するものであり、第2増幅器
14は周波数fn 〜fz の受信信号を増幅するものであ
る。
The first amplifier 13 has a frequency f of the signal frequencies f 1 to f z of the respective speech channels shown in FIG.
It is intended for amplifying the received signal of 1 ~f m, the second amplifier 14 amplifies the received signal in the frequency f n ~f z.

【0020】同一エリア内の多数の移動局4からは、各
々異なる周波数f1 〜fz の電波信号が送られて来るの
で、それらをアンテナ7により受信し、ハイブリッド回
路11で周波数f1 〜fm の信号と周波数fn 〜fz
信号とのグループに分岐し、この分岐された周波数f1
〜fm の信号を第1増幅器13で増幅し、周波数fn
z の信号を第2増幅器14で増幅するようになってい
る。
[0020] From a number of mobile stations 4 within the same area, each because radio signals of different frequencies f 1 ~f z is sent, they were received by the antenna 7, the frequency f 1 in the hybrid circuit 11 ~f The signal of m and the signals of frequencies f n to f z are branched into groups, and the branched frequencies f 1
~ F m signal is amplified by the first amplifier 13, frequency f n ~
The signal of f z is amplified by the second amplifier 14.

【0021】また、第1及び第2増幅器13,14で増
幅された信号はハイブリッド回路12で合成され、変復
調装置2を介して制御装置3へ伝送されるようになって
いる。
The signals amplified by the first and second amplifiers 13 and 14 are combined in the hybrid circuit 12 and transmitted to the controller 3 via the modulator / demodulator 2.

【0022】通常の通信には、周波数f1 〜fm のチャ
ネルの信号が使用され、周波数fn〜fz の信号は空き
チャネルとなっている。また、制御装置3は、変復調装
置2を介して送られてくる個々の受信信号のレベルを常
時検出しており、この検出レベルが基準レベル以上とな
った場合に、基準レベル以上となった周波数のチャネル
で通信を行っている移動局4に対して、空きチャネルに
切り替える指示を行う制御信号を出力する機能も有して
いる。
Signals of channels of frequencies f 1 to f m are used for normal communication, and signals of frequencies f n to f z are idle channels. Further, the control device 3 constantly detects the level of each received signal sent via the modulation / demodulation device 2, and when the detected level becomes equal to or higher than the reference level, the frequency which becomes equal to or higher than the reference level. It also has a function of outputting a control signal for instructing the mobile station 4 communicating with the channel to switch to the idle channel.

【0023】但し、基準レベルとは、通常の通信に使用
されている周波数f1 〜fm の信号を増幅する第1増幅
器13が飽和状態となった際に出力される信号レベルで
ある。
However, the reference level is a signal level output when the first amplifier 13 for amplifying the signals of the frequencies f 1 to f m used for normal communication is saturated.

【0024】このような構成において、制御装置3が基
準レベル以上の信号を検出したとする。この検出された
信号が、図3に示すように、通常の通信に使用されてい
る周波数f1 〜fm の内、周波数fg の信号であったと
する。
In such a configuration, it is assumed that the control device 3 detects a signal having a reference level or higher. As shown in FIG. 3, it is assumed that the detected signal is a signal of frequency f g among frequencies f 1 to f m used for normal communication.

【0025】この場合、制御装置3から空きチャネルの
何れかの周波数fn 〜fz に切り替える制御信号が、変
復調装置2を介して送受信装置1の送信側増幅器5に送
られて増幅された後、アンテナ6から電波送信される。
この電波送信された制御信号が該当する移動局4で受信
されると、移動局4は、制御信号が指示する空きチャネ
ルの周波数に切り替える。例えば図3に示すように周波
数fp に切り替えたとする。
In this case, after the control signal for switching from the control device 3 to one of the frequencies f n to f z of the empty channels is sent to the transmission side amplifier 5 of the transmission / reception device 1 via the modulation / demodulation device 2, and is amplified. A radio wave is transmitted from the antenna 6.
When the control signal transmitted by radio waves is received by the corresponding mobile station 4, the mobile station 4 switches to the frequency of the idle channel designated by the control signal. For example, assume that the frequency is switched to the frequency f p as shown in FIG.

【0026】この切り替えによって移動局4は周波数f
p の信号で通信を行うことになる。空きチャネルであっ
た周波数fp の信号は、送受信装置1のハイブリッド回
路11を介して第2増幅器14へ入力されて増幅され
る。
By this switching, the mobile station 4 has the frequency f.
Communication will be performed with the signal of p . The signal of the frequency f p , which was an empty channel, is input to the second amplifier 14 via the hybrid circuit 11 of the transmission / reception device 1 and amplified.

【0027】第2増幅器14は第1増幅器13よりも利
得がかなり小さいので、この際の増幅においては、第1
増幅器13のように飽和状態となることはない。即ち、
従来のように、送受信装置1に近い移動局4からの大レ
ベルの信号を受信した場合に、受信側の増幅器が飽和状
態となり、高調波が生じ、これが他のチャネルの信号に
影響を及ぼし、適正な通信が行えなくなるといったこと
がなくなる。
Since the gain of the second amplifier 14 is considerably smaller than that of the first amplifier 13, in the amplification at this time,
It does not become saturated like the amplifier 13. That is,
As in the conventional case, when a high level signal is received from the mobile station 4 close to the transmitter / receiver 1, the amplifier on the receiving side is saturated and a harmonic is generated, which affects the signals of other channels, It will not happen that proper communication cannot be performed.

【0028】[0028]

【発明の効果】以上説明したように、本発明によれば、
基地局の増幅器によって各々異なる周波数の受信信号を
共通増幅した際に増幅器が飽和状態となることを防止す
ることができるので、増幅器が飽和状態となって高調波
が生じ、これが他の周波数の信号に影響を及ぼすことが
なくなり、適正な通信を行うことができる効果がある。
As described above, according to the present invention,
Since it is possible to prevent the amplifier from becoming saturated when the received signals of different frequencies are commonly amplified by the amplifier of the base station, the amplifier becomes saturated and harmonics are generated. There is an effect that proper communication can be performed without affecting the communication.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例による移動通信システムのブ
ロック構成図である。
FIG. 1 is a block diagram of a mobile communication system according to an embodiment of the present invention.

【図2】図1に示す受信側の第1及び第2増幅器により
増幅される各信号の周波数スペクトル図である。
FIG. 2 is a frequency spectrum diagram of each signal amplified by the first and second amplifiers on the receiving side shown in FIG.

【図3】図1に示す基地局と移動局との通信周波数の切
り替え動作を説明するための図である。
FIG. 3 is a diagram for explaining a communication frequency switching operation between a base station and a mobile station shown in FIG.

【図4】従来の移動通信システムのブロック構成図であ
る。
FIG. 4 is a block diagram of a conventional mobile communication system.

【符号の説明】[Explanation of symbols]

2 変復調装置 3 制御装置 4 移動局 11 分岐手段 12 合成手段 13 第1増幅器 14 第2増幅器 2 modulator / demodulator 3 controller 4 mobile station 11 branching means 12 combining means 13 first amplifier 14 second amplifier

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 通信制御を司る主局に配線接続された基
地局と、基地局の電波エリア内の多数の移動局とで交信
される各々周波数の異なる各信号を、送受信側各々1つ
の増幅器で共通増幅して通信を行う移動通信システムに
おいて、 多数の移動局が通信を行うための各々異なる周波数の信
号を、通常使用する周波数の第1信号群と、通常使用し
ない周波数の第2信号群とに分岐する分岐手段(11)と、 該第1信号群を増幅する受信側の第1増幅器(13)と、 該第1増幅器(13)よりも利得が小さく、かつ該第2信号
群を増幅する受信側の第2増幅器(14)と、 該第1及び第2増幅器(13,14) から出力される信号を合
成する合成手段(12)とを基地局に設け、 該合成手段(12)から出力される各々異なる多数の周波数
の信号を変復調装置(2) を介して受信し、この受信され
た信号のレベルを個々に検出し、この検出レベルがある
基準レベル以上となった場合に、基準レベル以上となっ
た周波数の信号を送出している移動局に対して、現在使
用中の周波数を前記通常使用しない周波数に切り替える
指示を行う制御装置(3) を主局に設けたことを特徴とす
る移動通信システム。
1. An amplifier for transmitting and receiving signals of different frequencies, which are communicated between a base station hard-wired to a main station that controls communication and a large number of mobile stations within the radio area of the base station. In a mobile communication system in which communication is performed by commonly amplifying with a plurality of mobile stations, a plurality of mobile stations perform communication with signals of different frequencies, a first signal group of frequencies normally used and a second signal group of frequencies not normally used. Branching means (11) for branching to, a first amplifier (13) on the receiving side for amplifying the first signal group, and a second signal group having a gain smaller than that of the first amplifier (13). The base station is provided with a second amplifier (14) on the receiving side for amplification and a synthesizing means (12) for synthesizing the signals output from the first and second amplifiers (13, 14). ), The signals of a large number of different frequencies are received via the modulator / demodulator (2). Detected signal level individually, and when this detected level exceeds a certain reference level, the frequency currently in use is sent to the mobile station transmitting the signal of the frequency above the reference level. A mobile communication system characterized in that a control device (3) for instructing switching to a frequency not normally used is provided in a main station.
【請求項2】 前記基準レベルを、前記第1増幅器(13)
が飽和状態となった際に出力される信号レベルとしたこ
とを特徴とする請求項1記載の移動通信システム。
2. The reference level is set to the first amplifier (13).
The mobile communication system according to claim 1, wherein the signal level is output when the signal is saturated.
JP4154672A 1992-06-15 1992-06-15 Mobile communication system Withdrawn JPH05347580A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4154672A JPH05347580A (en) 1992-06-15 1992-06-15 Mobile communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4154672A JPH05347580A (en) 1992-06-15 1992-06-15 Mobile communication system

Publications (1)

Publication Number Publication Date
JPH05347580A true JPH05347580A (en) 1993-12-27

Family

ID=15589383

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4154672A Withdrawn JPH05347580A (en) 1992-06-15 1992-06-15 Mobile communication system

Country Status (1)

Country Link
JP (1) JPH05347580A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4838810A (en) * 1987-04-30 1989-06-13 Hirose Electric Co, Ltd. Coupling engagement mechanism for electric connector
KR100450934B1 (en) * 2000-12-28 2004-10-02 삼성전자주식회사 A high efficiency stage-switching cdma power amplifier

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4838810A (en) * 1987-04-30 1989-06-13 Hirose Electric Co, Ltd. Coupling engagement mechanism for electric connector
KR100450934B1 (en) * 2000-12-28 2004-10-02 삼성전자주식회사 A high efficiency stage-switching cdma power amplifier

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Legal Events

Date Code Title Description
A300 Withdrawal of application because of no request for examination

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 19990831