Variable filter
合集下载
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
申请人：LK PRODUCTS OY 地址：FI 国籍：FI 代理机构：Frain, Timothy John 更多信息请下载全文后查看
专利内容由知识产权出版社提供
专利名称：Variable filter 发明人：Ervasti, Kimm：EP 066564 3B 1 公开日：19981216
摘要：An advantageous embodiment of the invention is the filter of the receiver branch of the duplex filter in a multi-channel radio transmitter/receiver having reception and transmission bands composed of plural radio-frequency channels. In the first state of the filter, when the radio transmitter/receiver is only receiving radio signals, the width of the pass band of the filter corresponds to said reception band. In the second state, in which the radio transmitter/receiver additionally transmits radio signals, the pass band of the filter is switched by current control (+ I DC) to cover only part of the reception band. By constructing the filter in the manner proposed it is possible to use current control in the first resonator (HX 1) in the filter of the receiver branch. Because of its power consumption current control is otherwise unsuitable for use in e.g. the duplex filter of a portable radio-telephone.
专利内容由知识产权出版社提供
专利名称：Variable filter 发明人：Ervasti, Kimm：EP 066564 3B 1 公开日：19981216
摘要：An advantageous embodiment of the invention is the filter of the receiver branch of the duplex filter in a multi-channel radio transmitter/receiver having reception and transmission bands composed of plural radio-frequency channels. In the first state of the filter, when the radio transmitter/receiver is only receiving radio signals, the width of the pass band of the filter corresponds to said reception band. In the second state, in which the radio transmitter/receiver additionally transmits radio signals, the pass band of the filter is switched by current control (+ I DC) to cover only part of the reception band. By constructing the filter in the manner proposed it is possible to use current control in the first resonator (HX 1) in the filter of the receiver branch. Because of its power consumption current control is otherwise unsuitable for use in e.g. the duplex filter of a portable radio-telephone.